code: def to_frame(self, frame, current_frame=None, **kwargs):
          
  
          from ..potential.frame.builtin import transformations as frame_trans
  
          if ((inspect.isclass(frame) and issubclass(frame, coord.BaseCoordinateFrame)) or
                  isinstance(frame, coord.BaseCoordinateFrame)):
              import warnings
              warnings.warn("This function now expects a "
                            "`gala.potential.FrameBase` instance. To transform to"
                            " an Astropy coordinate frame, use the "
                            "`.to_coord_frame()` method instead.",
                            DeprecationWarning)
              return self.to_coord_frame(frame=frame, **kwargs)
  
          if self.frame is None and current_frame is None:
              raise ValueError("If no frame was specified when this {} was "
                               "initialized, you must pass the current frame in "
                               "via the current_frame argument to transform to a "
                               "new frame.")
  
          elif self.frame is not None and current_frame is None:
              current_frame = self.frame
  
          name1 = current_frame.__class__.__name__.rstrip('Frame').lower()
          name2 = frame.__class__.__name__.rstrip('Frame').lower()
          func_name = "{}_to_{}".format(name1, name2)
  
          if not hasattr(frame_trans, func_name):
              raise ValueError("Unsupported frame transformation: {} to {}"
                               .format(current_frame, frame))
          else:
              trans_func = getattr(frame_trans, func_name)
  
          pos, vel = trans_func(current_frame, frame, self, **kwargs)
          return PhaseSpacePosition(pos=pos, vel=vel, frame=frame)
docs: Transform to a new reference frame.
  
          Parameters
          ----------
          frame : `~gala.potential.FrameBase`
              The frame to transform to.
          current_frame : `gala.potential.CFrameBase`
              The current frame the phase-space position is in.
          **kwargs
              Any additional arguments are passed through to the individual frame
              transformation functions (see:
              `~gala.potential.frame.builtin.transformations`).
  
          Returns
          -------
          psp : `gala.dynamics.CartesianPhaseSpacePosition`
              The phase-space position in the new reference frame.