def bg_class(self, _):
raise ReadOnlyAttributeError("Cannot set a new background class. "
"Initialize a new ImagePair object.")
def image(self, _):
raise ReadOnlyAttributeError("Manually setting the image attribute "
"is not allowed. Initialize a new "
"ImagePair object.")
def labels(self, _):
raise ReadOnlyAttributeError("Manually setting the labels "
"attribute is not allowed. "
"Initialize a new ImagePair object.")
def header(self, header):
raise ReadOnlyAttributeError("Manually setting the header attribute "
"is not allowed. Initialize a new "
"ImagePair object.")
