code: /*
  RequireThis
  checkFields = (default)true
  checkMethods = (default)true
  validateOnlyOverlapping = (default)true
  
  
  */
  
  package com.puppycrawl.tools.checkstyle.checks.coding.requirethis;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.stream.Collectors;
  
  public class InputRequireThisMethodReferences { // ok
      private Set<String> tags = Collections.unmodifiableSortedSet(
          Arrays.stream(new String[] {"br", "li", "dt", "dd", "hr", "img", "p", "td", "tr", "th",})
              .collect(Collectors.toCollection(TreeSet::new)));
  
      public InputRequireThisMethodReferences(Set<String> tags) {
          tags = tags; // violation 'Reference to instance variable 'tags' needs "this.".'
      }
  
      public InputRequireThisMethodReferences() {
          this.tags = Arrays.stream(
              new String[] {"br", "li", "dt", "dd", "hr", "img", "p", "td", "tr", "th",})
              .collect(Collectors.toCollection(TreeSet::new));
      }
  }
  