def from_image_name(cls, png_image_name):
        """Return AlphaMask instance using given image name.

        Works by getting a surface from the image name,
        retrieving its alpha values and passing such values
        to the class constructor, returning the resulting
        instance.

        Parameters
        ==========
        png_image_name (string)
            name of .png image representing the mask.
        """
        ### instantiate and return an AlphaMask object
        ### from a surface loaded using the image name;
        ###
        ### the image is loaded with the 'use_alpha' option
        ### on, so the values of the alpha channel are
        ### available

        return cls.from_surface((IMAGE_SURFS_DB[png_image_name][{"use_alpha": True}]))
Return AlphaMask instance using given image name.

        Works by getting a surface from the image name,
        retrieving its alpha values and passing such values
        to the class constructor, returning the resulting
        instance.

        Parameters
        ==========
        png_image_name (string)
            name of .png image representing the mask.
        
nodezator/alphamask/main.py