in core/config/base_config.py [0:0]
def _field_data_map(cls, field_data_name):
"""Create a map of fields with provided the field data."""
schema = cls.schema()
one_of = collections.defaultdict(list)
for field, fdata in schema["properties"].items():
if field_data_name in fdata:
one_of[fdata[field_data_name]].append(field)
return one_of