Gets the name of a primary CodeQL class to which this element belongs.
For most elements, this is simply the most precise syntactic category to
which they belong; for example,
AddExpr is a primary class, but
BinaryOperation is not.
If no primary classes match, this predicate has no result. If multiple primary classes match, this predicate can have multiple results.
getPrimaryQlClasses, which is better to use in most cases.