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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_field_mapping(self, schema):
 """Get mapping for single field schema. :param schema: field schema """

        if 'mapping' in schema:
            return schema['mapping']
        elif schema['type'] == 'dict' and 'schema' in schema:
            return self._get_mapping(schema['schema'])
        elif schema['type'] == 'list' and 'schema' in schema.get('schema', {}):
            return self._get_mapping(schema['schema']['schema'])
        elif schema['type'] == 'datetime':
            return {'type': 'date'}
        elif schema['type'] == 'string' and schema.get('unique'):
            return {'type': 'string', 'index': 'not_analyzed'}