code: def purposes_for_layer(layer_geometry_key):
      
      return_value = []
      for layer_purpose in layer_purposes:
          layer_geometry_keys = [
              i['key'] for i in layer_purpose['allowed_geometries']]
          if layer_geometry_key in layer_geometry_keys:
              return_value.append(layer_purpose['key'])
  
      return sorted(return_value)
docs: Get purposes of a layer geometry id.
  
      :param layer_geometry_key: The geometry id
      :type layer_geometry_key: str
  
      :returns: List of suitable layer purpose.
      :rtype: list