     mapOfFundamentalFrequencies[roundedFrequency] = frequencies
   }
 
-
   /// Chooses the best fundamental frequency based on what has been added to the
   /// mapOfFundamentalFrequencies.
-  private func chooseBestFundamentalFrequency() -> Double{
+  private func chooseBestFundamentalFrequency() -> Double {
     // mapOfFundamentalFrequencies contains one or more approximate frequencies (keys),
     // each of which is associated with one or more actual frequencies. The number of
     // actual frequencies corresponds to the number of harmonic ratios that indicate that

    // of actual frequencies, we could choose the one with the lower approximate frequency.
    var bestFrequencies: [Double] = []

    mapOfFundamentalFrequencies.forEach { (key: Int, frequencies: [Double]) in
      if (frequencies.count > bestFrequencies.count) {
        bestFrequencies = frequencies
      }
    }

  private static func gcd(_ a: Int, _ b: Int) -> Int {
    var a = a
    var b = b
    while b > 0 {
      let temp = b
      b = a % b
      a = temp
