ere is no return value in this
        case.

        When invoked with the blocking argument set to true, do the same thing
        as when called without arguments, and return true.

        When invoked with the blocking argument set to false, do not block. If a
        call without an argument would block, return false immediately;
        otherwise, do the same thing as when called without arguments, and
        return true.

        When invoked with the floating-point timeout argument set to a positive
        value, block for at most the number of seconds specified by timeout
        and as long as the lock cannot be acquired.  Return true if the lock has
        been acquired, false if the timeout has elapsed.

        é