<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def dtcurrent(self, value):
 """Set value of `dtcurrent`, update derivatives if needed."""

        assert isinstance(value, bool)
        if value and self.dparamscurrent:
            raise RuntimeError("Can't set both dparamscurrent and dtcurrent True")
        if value != self.dtcurrent:
            self._dtcurrent = value
            self._updateInternals()