Method tidy

tfjs-core/src/engine.ts:441–475

(nameOrFn: string|ScopeFn<T>, fn?: ScopeFn<T>)

  }

  tidy<T extends TensorContainer>(nameOrFn: string|ScopeFn<T>, fn?: ScopeFn<T>):
      T {
    let name: string = null;
    if (fn == null) {
      // Called with only 1 argument.
      if (typeof nameOrFn !== 'function') {
        throw new Error('Please provide a function to tidy()');
      }
      fn = nameOrFn;
    } else {
      // Called with 2 arguments.
      if (typeof nameOrFn !== 'string' && !(nameOrFn instanceof String)) {
        throw new Error(
            'When calling with two arguments, the first argument ' +
            'to tidy() must be a string');
      }
      if (typeof fn !== 'function') {
        throw new Error(
            'When calling with two arguments, the 2nd argument ' +
            'to tidy() must be a function');
      }
      name = nameOrFn as string;
      // TODO(nsthorat,smilkov): Do operation logging and performance
      // profiling.
    }
    let result: T;
    return this.scopedRun(
        () => this.startScope(name), () => this.endScope(result), () => {
          result = fn();
          if (result instanceof Promise) {
            console.error('Cannot return a Promise inside of tidy.');
          }
          return result;
        });
  }

  private scopedRun<T>(start: () => void, end: () => void, f: () => T): T {
    start();