How to use the skatejs.prop.boolean function in skatejs

return {
      notesInOctave: prop.number({ attribute: true, default: 12 }),
      raisedNotes: prop.array({ attribute: true, default: [1,3,6,8,10] }),
      octaves: prop.number({ attribute: true, default: 2 }),
      sweep: prop.number({ attribute: true, default: Math.PI/2,
        deserialize (val) {
          return val*Math.PI/180;
        },
        serialize (val) {
          return val*180/Math.PI;
        }
      }),
      depth: prop.number({ attribute: true, default: 100 }),
      width: prop.number({ attribute: true, default: 500 }),
      overlapping: prop.number({ attribute: true, default: 0.5 }),
      pie: prop.boolean({attribute: true, default: false}),
      synth: prop.boolean({attribute: true, default: false}),
      transitionTime: prop.number({attribute: true, default: 750}),
      baseTone: prop.number({attribute: true, default: 32.70375}),
      baseKey: prop.number({attribute: true, default: 0}),
      leftmostKey: prop.number({attribute: true, default: 3*12}),
      keyStyle: prop.string({attribute: true})
    };
  }
  connectedCallback () {

notesInOctave: prop.number({ attribute: true, default: 12 }),
      raisedNotes: prop.array({ attribute: true, default: [1,3,6,8,10] }),
      octaves: prop.number({ attribute: true, default: 2 }),
      sweep: prop.number({ attribute: true, default: Math.PI/2,
        deserialize (val) {
          return val*Math.PI/180;
        },
        serialize (val) {
          return val*180/Math.PI;
        }
      }),
      depth: prop.number({ attribute: true, default: 100 }),
      width: prop.number({ attribute: true, default: 500 }),
      overlapping: prop.number({ attribute: true, default: 0.5 }),
      pie: prop.boolean({attribute: true, default: false}),
      synth: prop.boolean({attribute: true, default: false}),
      transitionTime: prop.number({attribute: true, default: 750}),
      baseTone: prop.number({attribute: true, default: 32.70375}),
      baseKey: prop.number({attribute: true, default: 0}),
      leftmostKey: prop.number({attribute: true, default: 3*12}),
      keyStyle: prop.string({attribute: true})
    };
  }
  connectedCallback () {