def _IsPresent(item):
if item[<NUM_LIT:0>].label == _FieldDescriptor.LABEL_REPEATED:<EOL><INDENT>return bool(item[<NUM_LIT:1>])<EOL><DEDENT>elif item[<NUM_LIT:0>].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:<EOL><INDENT>return item[<NUM_LIT:1>]._is_present_in_parent<EOL><DEDENT>else:<EOL><INDENT>return True<EOL><DEDENT>
Given a (FieldDescriptor, value) tuple from _fields, return true if the
    value should be included in the list returned by ListFields().