def edit(newTitle, newBody, newAuthor, newTags):
    """
        Change the contents of this blurb to refer to a new body, title, and
        author.

        @param newTitle: the title of the new blurb.
        @type newTitle: L{unicode}

        @param newBody: the body text of the new blurb.
        @type newBody: L{unicode}

        @param newAuthor: the primary role of the entity which is attempting
        to create the child posting.
        @type newAuthor: L{xmantissa.sharing.Role}

        @param newTags: the tags of the new blurb
        @type newTags: sequence of C{unicode}
        """
