<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def has_raster(self):
 """True if any of the assets is type 'raster'."""

        return any(asset.get('type') == RASTER_TYPE for asset in self.assets.values())