code: def get_asset_path(self, filename):
          
          if os.path.exists(os.path.join(self._asset_path, filename)):
              return os.path.join(self._asset_path, filename)
          else:
              raise AssetNotFoundError(
                  u("Cannot find asset: {0}").format(filename))
docs: Get the full system path of a given asset if it exists.  Otherwise it throws 
          an error.
  
          Args:
              filename (str) - File name of a file in /assets folder to fetch the path for.
  
          Returns:
              str - path to the target file.
  
          Raises:
              AssetNotFoundError - if asset does not exist in the asset folder.
  
          Usage::
              path = WTF_ASSET_MANAGER.get_asset_path("my_asset.png")
              # path = /your/workspace/location/WTFProjectName/assets/my_asset.png