code: public static Matcher<AssertTree> assertionWithCondition(
        final Matcher<ExpressionTree> conditionMatcher) {
      return new Matcher<AssertTree>() {
        @Override
        public boolean matches(AssertTree tree, VisitorState state) {
          return conditionMatcher.matches(tree.getCondition(), state);
        }
      };
    }
docs: Matches an assertion AST node if the given matcher matches its condition.
  
  @param conditionMatcher The matcher to apply to the condition in the assertion, e.g. in "assert
  false", the "false" part of the statement