How to use the st/auto_chords.AutoChords.coerceChord function in st

state.position += duration
          break
        }
        case "keySignature": {
          state.keySignature = new KeySignature(+command[1])
          break
        }
        case "timeSignature": {
          let [, perBeat, noteValue] = command
          state.beatsPerNote = 4 / noteValue
          state.beatsPerMeasure = state.beatsPerNote * perBeat
          break
        }
        case "macro": {
          let [, macroName] = command
          let chord = AutoChords.coerceChord(macroName)

          if (chord) {
            if (!song.autoChords) {
              song.autoChords = []
            }
            song.autoChords.push([state.position, chord])
          }

          break
        }
        default: {
          console.warn("Got unknown command when parsing song", command)
        }
      }
    }

      [["Cb", "dimM7"], () => AutoChords.coerceChord("cbdimM7")],
    ].map(function([expected, fn]) {

      [["B", "m"], () => AutoChords.coerceChord("bm")],
      [["Fb", "M"], () => AutoChords.coerceChord("fbM")],

      [["G#", "m"], () => AutoChords.coerceChord("g#m")],
      [["Cb", "dimM7"], () => AutoChords.coerceChord("cbdimM7")],

      [["G", "M"], () => AutoChords.coerceChord("g")],
      [["A", "M"], () => AutoChords.coerceChord("aM")],

      [["Fb", "M"], () => AutoChords.coerceChord("fbM")],
      [["G#", "m"], () => AutoChords.coerceChord("g#m")],

      [["A", "M"], () => AutoChords.coerceChord("aM")],
      [["B", "m"], () => AutoChords.coerceChord("bm")],

      [undefined, () => AutoChords.coerceChord("hello world")],
      [["G", "M"], () => AutoChords.coerceChord("g")],