parameters: (self)
docstring: Returns whether the expansion is composed of static string content.
  
          This is always True for StringExpansion. It will be True for Expansion
          only if all elements of that Expansion are static strings.
docstring_summary: Returns whether the expansion is composed of static string content.
docstring_tokens: Returns whether the expansion is composed of static string content .
function: def is_static_string(self):
          """Returns whether the expansion is composed of static string content.
  
          This is always True for StringExpansion. It will be True for Expansion
          only if all elements of that Expansion are static strings.
          """
          raise Exception('Must be implemented in child class.')
function_tokens: def is_static_string ( self ) : raise Exception ( 'Must be implemented in child class.' )