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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _write_validate(self):
 """In addition to constructor validation steps, run validation steps for writing."""

        if self.colorspace is None:
            msg = ("Writing colr boxes without enumerated "
                   "colorspaces is not supported at this time.")
            self._dispatch_validation_error(msg, writing=True)

        if self.icc_profile is None:
            if self.colorspace not in [SRGB, GREYSCALE, YCC]:
                msg = ("Colorspace should correspond to one of SRGB, "
                       "GREYSCALE, or YCC.")
                self._dispatch_validation_error(msg, writing=True)

        self._validate(writing=True)