code: function printTowerReport(profile) {
    const averageGrade = profile.calculateAverageGrade();
    if (!averageGrade) {
      return;
    }
  
    const averageGradeLetter = getGradeLetter(averageGrade);
    printLine(`Your average grade for this tower is: ${averageGradeLetter}\n`);
  
    Object.keys(profile.currentEpicGrades)
      .sort()
      .forEach(levelNumber => {
        const grade = profile.currentEpicGrades[levelNumber];
        const gradeLetter = getGradeLetter(grade);
        printLine(`  Level ${levelNumber}: ${gradeLetter}`);
      });
  
    printLine('\nTo practice a level, use the -l option.');
  }
docs: Prints the tower report.
  
  @param {Profile} profile The profile.