code: def get(self, name, **kwargs):
          
          name = self._prefix + name
          if name not in self._params:
              self._params[name] = symbol.Variable(name, **kwargs)
          return self._params[name]
docs: Get the variable given a name if one exists or create a new one if missing.
  
          Parameters
          ----------
          name : str
              name of the variable
          **kwargs :
              more arguments that's passed to symbol.Variable