function isLength(value) {
  return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
}
Checks if `value` is a valid array-like length.

**Note:** This function is based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).

@private
@param {*} value The value to check.
@returns {boolean} Returns `true` if `value` is a valid length, else `false`.