getNormalizedKeyName(keyName) {
    const keyState = this.keyStates[keyName];

    if (keyState) {
      return keyName;
    } else {
      const keyAlias = this.keyAliases[keyName];

      if (keyAlias) {
        return keyAlias;
      } else {
        return keyName;
      }
    }
  }
A normalized version of the key, achieved by comparing it to the list of known
aliases for the keys in the combination
@param {ReactKeyName} keyName Name of the key to normalize
@returns {ReactKeyName} Normalized key name