def HasField(self, field_name):
    'Checks if a certain field is set for the message.\n\n    For a oneof group, checks if any field inside is set. Note that if the\n    field_name is not defined in the message descriptor, :exc:`ValueError` will\n    be raised.\n\n    Args:\n      field_name (str): The name of the field to check for presence.\n\n    Returns:\n      bool: Whether a value has been set for the named field.\n\n    Raises:\n      ValueError: if the `field_name` is not a member of this message.\n    '
    raise NotImplementedError
Checks if a certain field is set for the message.

For a oneof group, checks if any field inside is set. Note that if the
field_name is not defined in the message descriptor, :exc:`ValueError` will
be raised.

Args:
  field_name (str): The name of the field to check for presence.

Returns:
  bool: Whether a value has been set for the named field.

Raises:
  ValueError: if the `field_name` is not a member of this message.
def HasField(self, field_name):
    'Checks if a certain field is set for the message.\n\n    For a oneof group, checks if any field inside is set. Note that if the\n    field_name is not defined in the message descriptor, :exc:`ValueError` will\n    be raised.\n\n    Args:\n      field_name (str): The name of the field to check for presence.\n\n    Returns:\n      bool: Whether a value has been set for the named field.\n\n    Raises:\n      ValueError: if the `field_name` is not a member of this message.\n    '
    raise NotImplementedError