code: def extend_variables(raw_variables, override_variables):
      
      if not raw_variables:
          override_variables_mapping = ensure_mapping_format(override_variables)
          return override_variables_mapping
  
      elif not override_variables:
          raw_variables_mapping = ensure_mapping_format(raw_variables)
          return raw_variables_mapping
  
      else:
          raw_variables_mapping = ensure_mapping_format(raw_variables)
          override_variables_mapping = ensure_mapping_format(override_variables)
          raw_variables_mapping.update(override_variables_mapping)
          return raw_variables_mapping
docs: extend raw_variables with override_variables.
          override_variables will merge and override raw_variables.
  
      Args:
          raw_variables (list):
          override_variables (list):
  
      Returns:
          dict: extended variables mapping
  
      Examples:
          >>> raw_variables = [{"var1": "val1"}, {"var2": "val2"}]
          >>> override_variables = [{"var1": "val111"}, {"var3": "val3"}]
          >>> extend_variables(raw_variables, override_variables)
              {
                  'var1', 'val111',
                  'var2', 'val2',
                  'var3', 'val3'
              }