Allocate storage entries for multiple thunks.

Concatenate several PDF documents together.

Parameters:
  `inputs`: A list of URIs to PDF documents.

Compress a PDF document according to a specific compression profile.

Parameters:
  `input`: URI to a PDF document to be compressed.
  `compression-profile`: Compression profile to use, possible choices are
  "text", "photo-grey", "photo". 

Retrieve metadata from a PDF document.

Parameters:
  `input`: URI to a PDF document.

Render an HTML document to a PDF document.

Parameters:
  `input`: URI to the HTML content to render.
  `base-uri`: Base URI to use when resolving relative URIs.

Render an HTML document to a PDF document using CSS2XSLFO and Apache FOP.

Parameters:
  `input`: URI to the HTML content to render.
  `base-uri`: Base URI to use when resolving relative URIs.

Digitally sign one or more PDF documents.

Parameters:
  `inputs`: Vector of URIs to PDF documents to be digitally signed.
  `certificate-alias`: Alias of the certificate in the keystore to use for
  signing.
  `reason`: PDF signature reason.

Split a PDF document into multiple documents.

Parameters:
  `input`: URI to a PDF document.
  `page-groups`: A vector of vectors, representing the output documents. Each
      element should itself be a vector that contains any of the following to
      represent the pages of the document:

      - integer: 1-based page index;
      - string: Page location such as "first" or "last";
      - 2-vector: A start and end page reference (of either preceeding type),
        representing an inclusive page span, which may also run backwards.

Stamp one or more documents with a watermark document.

Parameters:
  `inputs`: URIs to PDF documents to be stamped.
  `watermark`: URI to a PDF document to use as the stamp.

Generate JPEG thumbnails for a PDF document.

Parameters:
  `input`: URI to a PDF document.
  `dpi`: Pixel density of the thumbnail.