import re


def GetArgument(string):
  """Returns the value inside the first set of parentheses in a string.

  Args:
    string: String in the format "identifier(args)"

  Returns:
    args from string passed in. None if there were no parentheses.
  """
  match = re.match("\w+\(([^)]+)\)", string)
  if match:
    return match.group(1)
  return None