def is_organic(fragment):
<EOL>for a in fragment.GetAtoms():<EOL><INDENT>if a.GetAtomicNum() == <NUM_LIT:6>:<EOL><INDENT>return True<EOL><DEDENT><DEDENT>return False<EOL>
Return true if fragment contains at least one carbon atom.

    :param fragment: The fragment as an RDKit Mol object.