#fixed code
                              @Test
  public void standard_syntax() throws Exception {
    IfStatementTree tree = parse("if ($a) {}", PHPLexicalGrammar.IF_STATEMENT);

    assertThat(tree.ifToken().text()).isEqualTo("if");
    assertThat(expressionToString(tree.condition())).isEqualTo("($a)");
    assertThat(tree.statements()).hasSize(1);

    assertThat(tree.elseClause()).isNull();
    assertThat(tree.elseifClauses()).hasSize(0);
    assertThat(tree.endifToken()).isNull();
    assertThat(tree.eosToken()).isNull();
  }
#vulnerable code 
                              @Test
  public void standard_syntax() throws Exception {
    IfStatementTree tree = parse("if ($a) {} else {}", PHPLexicalGrammar.IF_STATEMENT);

    assertThat(tree.is(Kind.IF_STATEMENT)).isTrue();
    assertThat(tree.ifToken().text()).isEqualTo("if");
    assertThat(tree.condition()).isNotNull();
    assertThat(tree.statements()).hasSize(1);
    ElseClauseTree elseClause = tree.elseClause();
    assertThat(elseClause).isNotNull();
    assertThat(elseClause.is(Kind.ELSE_CLAUSE)).isTrue();
    assertThat(elseClause.statements()).hasSize(1);
    assertThat(tree.elseifClauses()).hasSize(0);
    assertThat(tree.colonToken()).isNull();
    assertThat(tree.endifToken()).isNull();
    assertThat(tree.eosToken()).isNull();
  } 
                            #location 11 
                            #vulnerability type NULL_DEREFERENCE