client/lib/query-manager/theme/key.js
function isDefaultOrNullQueryValue( value, key ) {
	return value === undefined || value === null || DEFAULT_THEME_QUERY[ key ] === value;
}
function isDefaultOrNullQueryValue( value, key ) {
	return value === undefined || value === null || DEFAULT_THEME_QUERY[ key ] === value;
}
Returns true if the specified key value query pair is identical to that of
the default theme query, is null, or is undefined.

@param  {*}       value Value to check
@param  {String}  key   Key to check
@return {Boolean}       Whether key value matches default query or is null