diff --git a/.gitignore b/.gitignore
index 59cfaec..c91b622 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@ cov_profile/
 
 node_modules/
 package-lock.json
+
+dest/
diff --git a/dest/fsm.d.ts b/dest/fsm.d.ts
deleted file mode 100644
index 47ba9a3..0000000
--- a/dest/fsm.d.ts
+++ /dev/null
@@ -1,46 +0,0 @@
-declare type StateTransitions<Context> = WeakMap<State<Context>, WeakSet<State<Context>>>;
-export declare const _states: unique symbol;
-export declare const _stateTransitions: unique symbol;
-export declare const _prevState: unique symbol;
-export declare const _currState: unique symbol;
-export declare class StateMachineBuilder<Context> {
-    [_states]: Map<string, Actions<Context>>;
-    [_stateTransitions]: Array<[string, Array<string>]> | undefined;
-    constructor();
-    withTransitions(transitions: Array<[string, Array<string>]>): this;
-    withStates(names: string[], actions?: Actions<Context>): this;
-    withState(name: string, actions?: Actions<Context>): this;
-    private addStateUnchecked;
-    build(currentStateName: string): StateMachine<unknown>;
-    private buildStates;
-    private buildTransitions;
-}
-export declare class StateMachine<Context> {
-    [_states]: State<Context>[];
-    [_stateTransitions]: StateTransitions<Context>;
-    [_prevState]: State<Context> | undefined;
-    [_currState]: State<Context>;
-    constructor(states: State<Context>[], transitions: StateTransitions<Context>, currentState: State<Context>);
-    changeState(sourceState: string | State<Context>, context?: Context): Promise<void>;
-    hasTransition(to: string | State<Context>): boolean;
-    allowedTransitionStates(): State<Context>[];
-}
-declare const _stateName: unique symbol;
-declare const _stateActions: unique symbol;
-interface Actions<Context> {
-    beforeExit?(fromState: State<Context>, toState: State<Context>, context: Context): boolean;
-    onEntry?(fromState: State<Context>, toState: State<Context>, context: Context): Promise<void> | void;
-}
-export declare class State<Context> {
-    [_stateActions]: Actions<Context>;
-    [_stateName]: string;
-    get name(): string;
-    constructor(name: string, actions?: Actions<Context>);
-    entry(fromState: State<Context>, toState: State<Context>, context: Context): Promise<void>;
-    exit(fromState: State<Context>, toState: State<Context>, context: Context): boolean;
-    toString(): string;
-    toJSON(): string;
-}
-export declare class FsmError extends Error {
-}
-export {};
diff --git a/dest/fsm.js b/dest/fsm.js
deleted file mode 100644
index 369f4ef..0000000
--- a/dest/fsm.js
+++ /dev/null
@@ -1,144 +0,0 @@
-"use strict";
-var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
-    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
-    return new (P || (P = Promise))(function (resolve, reject) {
-        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
-        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
-        step((generator = generator.apply(thisArg, _arguments || [])).next());
-    });
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.FsmError = exports.State = exports.StateMachine = exports.StateMachineBuilder = exports._currState = exports._prevState = exports._stateTransitions = exports._states = void 0;
-exports._states = Symbol("states");
-exports._stateTransitions = Symbol("state transitions");
-exports._prevState = Symbol("previous state");
-exports._currState = Symbol("current state");
-class StateMachineBuilder {
-    constructor() {
-        this[exports._states] = new Map();
-    }
-    withTransitions(transitions) {
-        this[exports._stateTransitions] = transitions;
-        return this;
-    }
-    withStates(names, actions) {
-        names.forEach((name) => this.addStateUnchecked(name, actions));
-        return this;
-    }
-    withState(name, actions) {
-        this.addStateUnchecked(name, actions);
-        return this;
-    }
-    addStateUnchecked(name, actions) {
-        const oldActions = this[exports._states].get(name);
-        return this[exports._states].set(name, Object.assign(Object.assign({}, oldActions), actions));
-    }
-    build(currentStateName) {
-        const states = this.buildStates();
-        const transitions = this.buildTransitions(states);
-        const currState = validStateFromName(states, currentStateName);
-        return new StateMachine(states, transitions, currState);
-    }
-    buildStates() {
-        return Array.from(this[exports._states].entries()).map((params) => new State(...params));
-    }
-    buildTransitions(states) {
-        const sourceTransitions = this[exports._stateTransitions] || [];
-        return new WeakMap(sourceTransitions.map(([from, toStates]) => [
-            validStateFromName(states, from),
-            new WeakSet(toStates.map(validStateFromName.bind(null, states))),
-        ]));
-    }
-}
-exports.StateMachineBuilder = StateMachineBuilder;
-class StateMachine {
-    constructor(states, transitions, currentState) {
-        this[exports._states] = states;
-        this[exports._stateTransitions] = transitions;
-        this[exports._currState] = currentState;
-    }
-    changeState(sourceState, context) {
-        return __awaiter(this, void 0, void 0, function* () {
-            const fromState = validState(this[exports._currState]);
-            const toState = validState(normalizeState(this[exports._states], sourceState));
-            if (!this.hasTransition(toState) ||
-                !fromState.exit(fromState, toState, context)) {
-                throw new FsmError(`cannot change state from "${fromState.name}" to "${toState.name}"`);
-            }
-            yield toState.entry(fromState, toState, context);
-            this[exports._currState] = toState;
-            this[exports._prevState] = fromState;
-        });
-    }
-    hasTransition(to) {
-        return hasTransition(this[exports._stateTransitions], this[exports._currState], validState(normalizeState(this[exports._states], to)));
-    }
-    allowedTransitionStates() {
-        const fromState = validState(this[exports._currState]);
-        return this[exports._states].filter(hasTransition.bind(null, this[exports._stateTransitions], fromState));
-    }
-}
-exports.StateMachine = StateMachine;
-const _stateName = Symbol("state name");
-const _stateActions = Symbol("state actions");
-class State {
-    constructor(name, actions = {}) {
-        this[_stateName] = name;
-        this[_stateActions] = actions;
-    }
-    get name() {
-        return this[_stateName];
-    }
-    entry(fromState, toState, context) {
-        return __awaiter(this, void 0, void 0, function* () {
-            const action = this[_stateActions].onEntry;
-            if (isFn(action)) {
-                yield action(fromState, toState, context);
-            }
-        });
-    }
-    exit(fromState, toState, context) {
-        const action = this[_stateActions].beforeExit;
-        return isFn(action) ? action(fromState, toState, context) : true;
-    }
-    toString() {
-        return this.name;
-    }
-    toJSON() {
-        return this.toString();
-    }
-}
-exports.State = State;
-function stateFromName(states, name) {
-    return states.find((state) => state.name === name);
-}
-function validStateFromName(states, name) {
-    return validState(stateFromName(states, name));
-}
-function normalizeState(states, state) {
-    return isStr(state) ? stateFromName(states, state) : state;
-}
-function validState(val) {
-    if (!isState(val)) {
-        throw new TypeError("an instance of State class is expected");
-    }
-    return val;
-}
-function isState(val) {
-    return val instanceof State;
-}
-function hasTransition(transitions, from, to) {
-    var _a;
-    return ((_a = transitions.get(from)) === null || _a === void 0 ? void 0 : _a.has(to)) || false;
-}
-function isStr(val) {
-    return typeof val === "string";
-}
-// deno-lint-ignore ban-types
-function isFn(val) {
-    return typeof val === "function";
-}
-class FsmError extends Error {
-}
-exports.FsmError = FsmError;