(a) Legislative immunity, affording protection under the Separation of Powers Doctrine and the Speech or Debate privilege, extends to all of a legislator's legislative acts, as defined in section three of this article.
(b) The Speech or Debate privilege, when it applies, is absolute and has two aspects:
(1) A member of the Legislature has immunity extending both to civil suits and criminal prosecutions for all actions within the legislative sphere, even though the conduct, if performed in other than a legislative context, would in itself be unconstitutional or otherwise contrary to criminal or civil statutes; and
(2) A member of the Legislature is provided a testimonial privilege that operates to protect those to whom it applies from being compelled to give testimony as to privileged matters and from being compelled to produce privileged documents.