Method sizeIfKnown

corpus/java/training/guava/io/ByteSource.java:168–171

Returns the size of this source in bytes, if the size can be easily determined without actually opening the data stream. The default implementation returns Optional#absent. Some sources, such as a file, may return a non-absent value. Note that in such cases, it is possible that th

()

   * @since 19.0
   */
  @Beta
  public Optional<Long> sizeIfKnown() {
    return Optional.absent();
  }

  /**
   * Returns the size of this source in bytes, even if doing so requires opening and traversing an