a legislative capacity. That, plaintiffs contend, is precisely what the board did in the instant case and hence they have no claim to legislative immunity. For the reasons that follow, we agree. The Seventh Circuit has provided little guidance on applying the so-called functional approach to absolute legislative immunity; so, we shall begin our analysis by reference to guidance from the Supreme Court and the approaches of the other federal circuit courts. In a context not involving legislative immunity, the Supreme Court observed that “[t]he essentials of the legislative function are the determination of the legislative policy and its formulation and promulgation as a defined and binding rule of conduct.” Yakus v. United States, 321 U.S. 414, 424, 64 S.Ct. 660, 667, 88 L.Ed. 834 (1944) (<HOLDING>). Similarly, in Prentis v. Atlantic Coast Line
holding a defendant is liable as a control person if the defendant had the power to control the general affairs of the entity primarily liable at the time the entity violated the securities laws but declining to decide whether power to control means simply abstract power to control or actual exercise of the power to control internal quotations omitted holding that when congress included provisions of compulsory testimony act of 1893 in the emergency price control act of 1942 it necessarily adopted settled judicial construction of the 1893 act holding that when a judicial office is created by legislative act or municipal ordinance  the office is regarded as a de facto office until the act or ordinance is declared invalid holding that the emergency price control act of 1942 did not unconstitutionally delegate the legislative power of congress to the office of price administration holding that the phrase  shall be granted in the injunctive enforcement provision of the emergency price control act of 1942 is less mandatory than a literal reading might suggest we cannot but think that if congress had intended to make such a drastic departure from the traditions of equity practice an unequivocal statement of its purpose would have been made