parameters: (self, index)
docstring: Make stream jump to a new location, saving old location.
          Switch back with pop().
docstring_summary: Make stream jump to a new location, saving old location.
          Switch back with pop().
docstring_tokens: Make stream jump to a new location saving old location . Switch back with pop () .
function: def push(self, index):
          """
          Make stream jump to a new location, saving old location.
          Switch back with pop().
          """
  
          self.calls.append(self.p) # save current index
          self.seek(index)
function_tokens: def push ( self , index ) : self . calls . append ( self . p ) # save current index self . seek ( index )