Values:
KIND_UNSPECIFIED (0):
Not specified. This value should be never
used.
KIND_MAP (1):
Map entity types allow mapping of a group of
synonyms to a reference value.
KIND_LIST (2):
List entity types contain a set of entries
that do not map to reference values. However,
list entity types can contain references to
other entity types (with or without aliases).
KIND_REGEXP (3):
Regexp entity types allow to specify regular
expressions in entries values.