def METHOD_NAME(self, layername, grassmapname=False, force=False):
    """
    Create a new layer and add it to the layer collection
    @param string name of the layer
    @param string optional name of a GRASS map layer (False if only local)
    @param boolean optional, whether to overwrite an existing layer
    """
    layer = garray.array()
    if grassmapname:
        self.grassmapnames[layername] = grassmapname
    self.setlayer(layername, layer, force)