code: def GetDefinitionByName(self, name):
      
      lookup_name = name.lower()
      if lookup_name not in self._definitions:
        lookup_name = self._aliases.get(name, None)
  
      return self._definitions.get(lookup_name, None)
docs: Retrieves a specific data type definition by name.
  
      Args:
        name (str): name of the data type definition.
  
      Returns:
        DataTypeDefinition: data type definition or None if not available.