hasNodes("(numberOfNodes > 0 ) && hasActor"),
hasElems("(count( elemTypes ) > 0)"),
hasDifferentElems("(count( elemTypes ) > 1)"),
hasNodes("(numberOfNodes > 0 ) && hasActor"),
hasElems("(count( elemTypes ) > 0)"),
hasDifferentElems("(count( elemTypes ) > 1)"),