def serialize_dict_keys(d, prefix="<STR_LIT>"):
keys = []<EOL>for k, v in d.iteritems():<EOL><INDENT>fqk = '<STR_LIT>' % (prefix, k)<EOL>keys.append(fqk)<EOL>if isinstance(v, dict):<EOL><INDENT>keys.extend(serialize_dict_keys(v, prefix="<STR_LIT>" % fqk))<EOL><DEDENT><DEDENT>return keys<EOL>
returns all the keys in a dictionary.

    >>> serialize_dict_keys({"a": {"b": {"c": 1, "b": 2} } })
    ['a', 'a.b', 'a.b.c', 'a.b.b']