@abc.abstractmethod<EOL><INDENT>def get_coordinate_conversion_session_for_type(self, source_coordinate_type, target_coordinate_type, proxy):<DEDENT>
return<EOL>
Gets an ``OsidSession`` associated with the coordinate conversion service and the given coordinate types.

        :param source_coordinate_type: the type of the source coordinate
        :type source_coordinate_type: ``osid.type.Type``
        :param target_coordinate_type: the type of the target coordinate
        :type target_coordinate_type: ``osid.type.Type``
        :param proxy: a proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: a ``CoordinateConversionSession``
        :rtype: ``osid.locale.CoordinateConversionSession``
        :raise: ``NullArgument`` -- ``source_coordinate_type,``  ``target_coordinate_type,`` or ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_coordinate_conversion()`` or ``supports_visible_federation()`` is ``false``
        :raise: ``Unsupported`` -- ``supports_coordinate_record_types_for_conversion(source_coordinate_type, target_coordinate_type)`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_coordinate_conversion()`` and
        ``supports_visible_federation()`` are ``true``.*