contains
Tests whether this ObjectTagContainer contains a tag with the given key.
Return
true if this tag container has a tag with the target key or at least if the tag existed at the time of this method call. false if at the time of this method call, this tag container did not have a tag with the target key.
Parameters
key
Key of the tag to test for.
Throws
If this Object does not exist.
If the parent bucket of this Object does not exist.
If an implementation specific exception is thrown. The implementation specific exception will be set to the thrown exception's 'cause' value.