def __set_current(self, current):
     self.command("CURR %s" % fmt(current))
 def __set_voltage(self, voltage):
     self.command("VOLT %s" % fmt(voltage))
 def __set_offset(self, offset):
     self.command("OFFS %s" % fmt(offset))
 def __set_frequency(self, frequency):
     self.command("FREQ %s" % fmt(frequency))
 def __set_amplitude(self, voltage):
     self.command("VOLT %s" % fmt(voltage))
 def apply(self, type, freq=None, amp=None, offset=None):
     if type not in FunctionGenerator.TYPES:
         raise ValueError("Type must be one of %s" % (TYPES,))
     self.command("APPL:%s %s,%s,%s" % (type, fmt(freq), fmt(amp), fmt(offset)))