"""
Meta-Features are classes that extend :class:`~revscoring.Datasource` and
implement common operations on other :class:`~revscoring.Datasource`.

dicts
+++++
.. automodule:: revscoring.datasources.meta.dicts

extractors
++++++++++
.. automodule:: revscoring.datasources.meta.extractors

filters
+++++++
.. automodule:: revscoring.datasources.meta.filters

frequencies
+++++++++++
.. automodule:: revscoring.datasources.meta.frequencies

mappers
+++++++
.. automodule:: revscoring.datasources.meta.mappers
"""
