break_stmt: "break"
break may only occur syntactically nested in a for
or while loop, but not nested in a function or class definition
within that loop.
It terminates the nearest enclosing loop, skipping the optional
else clause if the loop has one.
If a for loop is terminated by break, the loop control
target keeps its current value.
When break passes control out of a try statement
with a finally clause, that finally clause is executed
before really leaving the loop.