function getFunctionName(constructorFn) {
  var name = '';
  if (typeof constructorFn.name === 'undefined') {
    // Here we run a polyfill if constructorFn.name is not defined
    var match = String(constructorFn).match(functionNameMatch);
    if (match) {
      name = match[1];
    }
  } else {
    name = constructorFn.name;
  }

  return name;
}
### .getFunctionName(constructorFn)

Returns the name of a function.
This also includes a polyfill function if `constructorFn.name` is not defined.

@name getFunctionName
@param {Function} constructorFn
@namespace Utils
@api private