Determines if a given string is a valid D-Bus object path. You should ensure that a string is a valid D-Bus object path before passing it to Variant.newObjectPath.
A valid object path starts with / followed by zero or more sequences of characters separated by / characters. Each sequence must contain only the characters [A-Z][a-z][0-9]_. No sequence (including the one following the final / character) may be empty.