docs: private static ExpressionTree stripNullCheck(ExpressionTree expression, VisitorState state) {
      if (expression != null && expression.getKind() == METHOD_INVOCATION) {
        MethodInvocationTree methodInvocation = (MethodInvocationTree) expression;
        if (NON_NULL_MATCHER.matches(methodInvocation, state)) {
          return methodInvocation.getArguments().get(0);
        }
      }
      return expression;
    }