code: @Nonnull
    public static ImmutableKeyValueSource<Symbol, ByteSource> fromZip(final ZipFile zipFile) {
      return fromZip(zipFile, SymbolUtils.symbolizeFunction());
    }
docs: Creates a new source using a zip file where each value is located at an entry with the same
  name as the key. The caller must ensure that the zip file is not closed or modified, otherwise
  all behavior is undefined. All files in the zip file will be used; there is currently no way to
  exclude specific files. To specify a function that defines the mapping between keys and the
  entry used for their values, see {@link #fromZip(ZipFile, Function)}.
  
  @param zipFile the zip file to use as a source
  @return a new key-value source backed by the specified zip file
  @see #fromZip(ZipFile, Function)