parameters: (self, pos, filename)
return_statement: return self.forward(pos, filename)
docstring: @brief top API 
          @param pos cell locations, array of x locations and then y locations 
          @param filename suffix specifies the format
function: def __call__(self, pos, filename):
          """
          @brief top API 
          @param pos cell locations, array of x locations and then y locations 
          @param filename suffix specifies the format 
          """
          return self.forward(pos, filename)
function_tokens: def __call__ ( self , pos , filename ) : return self . forward ( pos , filename )