def METHOD_NAME(self):
    p =self.p
    cellIdx = self.cellIdx
    ldof = self.number_of_local_dofs()
    localEdge = self.mesh.ds.localEdge
    isEdgeDof = np.zeros((ldof, 6), dtype=np.bool_)
    for i in range(6):
        isEdgeDof[i,:] = (cellIdx[localEdge[-(i+1),0],:] == 0) & (cellIdx[localEdge[-(i+1),1],:] == 0 )
    return isEdgeDof