def mergeSimple(pdfs):
    """Given a list of PDFs, merges the documents into a new PDF, which is
    returned."""

def merge(pdfs, retain_numbering, remove_duplicate_fonts):
    """Merges the list of PDFs. If retain_numbering is True page labels are not
    rewritten. If remove_duplicate_fonts is True, duplicate fonts are merged.
    This is useful when the source documents for merging originate from the
    same source."""

def mergeSame(pdfs, retain_numbering, remove_duplicate_fonts, ranges):
    """The same as merge, except that it has an additional argument (a list of
    page ranges). This is used to select the pages to pick from each PDF. This
    avoids duplication of information when multiple discrete parts of a single
    source PDF are included."""

def selectPages(pdf, r):
    """Returns a new document which just those pages in the page range."""
