def metadata
      metadata = {}
      other_chunks.each do |chunk|
        metadata[chunk.keyword] = chunk.value if chunk.respond_to?(:keyword) && chunk.respond_to?(:value)
      end
      metadata
    end
def metadata
      metadata = {}
      other_chunks.each do |chunk|
        metadata[chunk.keyword] = chunk.value if chunk.respond_to?(:keyword) && chunk.respond_to?(:value)
      end
      metadata
    end
Returns all the textual metadata key/value pairs as hash.
 @return [Hash] A hash containing metadata fields and their values.