text: const mongoose = require('mongoose')
  const ObjectId = mongoose.Schema.Types.ObjectId
  
  const coachSchema = new mongoose.Schema({
      firstName: {type: String, required: true},
      lastName: {type: String, required: true, unique: true},
      country: {type: String, required: true},
      age: {type: Number, required: true},
      bithplace: {type: String, required: true},
      players: [{type: ObjectId, ref: 'Player', default: []}]
  }, { usePushEach: true })
  
  const Coach = mongoose.model('Coach', coachSchema)
  
  module.exports = Coach