function FibonacciHeap() {
    if (!(this instanceof FibonacciHeap)) {
      throw new SyntaxError('Constructor must be called with the new operator');
    } // initialize fields


    this._minimum = null;
    this._size = 0;
  }
Fibonacci Heap implementation, used interally for Matrix math.
@class FibonacciHeap
@constructor FibonacciHeap