def METHOD_NAME(name):
  """Validates the name against a regular expression object.
  If the name matches the regular expression, we return nothing.
  If the name fails to match, we generate an exception.
  Args:
    name: (str) name of variable or method
  Returns:
    (str) The name.
  Raises:
    ValidationError: An Error if name does not conform to style
  """
  if _VARNAME_REGEX.match(name) is None:
    raise ValidationError(
        'Variable %s does not conform to style guide' % name)
  return name