android/guava/src/com/google/common/collect/ForwardingSortedSet.java
@Override
  @Beta
  protected boolean standardContains(@NullableDecl Object object) {
    try {
      // any ClassCastExceptions are caught
      @SuppressWarnings("unchecked")
      SortedSet<Object> self = (SortedSet<Object>) this;
      Object ceiling = self.tailSet(object).first();
      return unsafeCompare(ceiling, object) == 0;
    } catch (ClassCastException | NoSuchElementException | NullPointerException e) {
      return false;
    }
  }
@Override
  @Beta
  protected boolean standardContains(@NullableDecl Object object) {
    try {
      // any ClassCastExceptions are caught
      @SuppressWarnings("unchecked")
      SortedSet<Object> self = (SortedSet<Object>) this;
      Object ceiling = self.tailSet(object).first();
      return unsafeCompare(ceiling, object) == 0;
    } catch (ClassCastException | NoSuchElementException | NullPointerException e) {
      return false;
    }
  }
@ Override @ Beta protected boolean standardContains ( @ NullableDecl Object object ) { try { // any ClassCastExceptions are caught @ SuppressWarnings ( "unchecked" ) SortedSet < Object > self = ( SortedSet < Object > ) this ; Object ceiling = self . tailSet ( object ) . first ( ) ; return unsafeCompare ( ceiling , object ) == 0 ; } catch ( ClassCastException | NoSuchElementException | NullPointerException e ) { return false ; } }
A sensible definition of {@link #contains} in terms of the {@code first()} method of {@link
#tailSet}. If you override {@link #tailSet}, you may wish to override {@link #contains} to
forward to this implementation.

@since 7.0
A sensible definition of { @link #contains } in terms of the { @code first () } method of { @link #tailSet } . If you override { @link #tailSet } you may wish to override { @link #contains } to forward to this implementation .