def pagecontext(page):
    """After a page is identified, corresponding context information must
        be gathered. Context can be saved in JSON files that have one-to-one
        mapping with content-pages, and/or it can be supplied by the content
        itself (many markups, like rst, markdown, allow authors to add 
        meta-data in their document). Refer to corresponding layout-plugin to
        know how pages are idenfitied from source layout.

        Returns back dictionary of ``context`` attributes.
        """
