parameters: (self, x: int)
docstring: Push element x to the back of queue.
docstring_summary: Push element x to the back of queue.
docstring_tokens: Push element x to the back of queue .
function: def push(self, x: int) -> None:
          """
          Push element x to the back of queue.
          """
          self.istk.append(x)
function_tokens: def push ( self , x : int ) -> None : self . istk . append ( x )