Function extract 

pub fn extract<'a, G>(
    pdf: &Pdf,
    new_ref: Box<dyn FnMut() -> Ref + 'a>,
    chunk_settings: ChunkSettings,
    write_xobject_group_cs: G,
    queries: &[ExtractionQuery],
) -> Result<ExtractionResult, ExtractionError>
where
    G: for<'b> FnMut(&mut Group<'b>),

Apply the extraction queries to the given PDF and return the results.