android/guava/src/com/google/common/hash/BloomFilter.java
@CanIgnoreReturnValue
  public boolean put(T object) {
    return strategy.put(object, funnel, numHashFunctions, bits);
  }
@CanIgnoreReturnValue
  public boolean put(T object) {
    return strategy.put(object, funnel, numHashFunctions, bits);
  }
Puts an element into this {@code BloomFilter}. Ensures that subsequent invocations of {@link
#mightContain(Object)} with the same element will always return {@code true}.

@return true if the Bloom filter's bits changed as a result of this operation. If the bits
changed, this is <i>definitely</i> the first time {@code object} has been added to the
filter. If the bits haven't changed, this <i>might</i> be the first time {@code object} has
been added to the filter. Note that {@code put(t)} always returns the <i>opposite</i>
result to what {@code mightContain(t)} would have returned at the time it is called.
@since 12.0 (present in 11.0 with {@code void} return type})