code: def set_chorus(self, nr=-1, level=-1.0, speed=-1.0, depth=-1.0, type=-1):
          
          set=0
          if nr>=0:
              set+=0b00001
          if level>=0:
              set+=0b00010
          if speed>=0:
              set+=0b00100
          if depth>=0:
              set+=0b01000
          if type>=0:
              set+=0b10000
          return fluid_synth_set_chorus_full(self.synth, set, nr, level, speed, depth, type)
docs: nr Chorus voice count (0-99, CPU time consumption proportional to this value)
          level Chorus level (0.0-10.0)
          speed Chorus speed in Hz (0.29-5.0)
          depth_ms Chorus depth (max value depends on synth sample rate, 0.0-21.0 is safe for sample rate values up to 96KHz)
          type Chorus waveform type (0=sine, 1=triangle)