What is the CALCRIM 915 instruction on self-defense?

The CALCRIM instruction is 915, labeled "Simple Assault (Penal Code 240)." It lists the four elements of the crime and then a possible element 5, which the instruction says to give when instructing on "self-defense or defense of another." And as to this, CALCRIM 915 has this "Instructional Duty" to the trial court: "If there is sufficient evidence of self-defense or defense of another, the court has a sua sponte duty to instruct on the defense." (See generally People v. Brooks (2017) 3 Cal.5th 1, 73.)