code: function parameterCount (body, limit) {
    var count = 0
    var index = 0
  
    while ((index = body.indexOf('&', index)) !== -1) {
      count++
      index++
  
      if (count === limit) {
        return undefined
      }
    }
  
    return count
  }
docs: Count the number of parameters, stopping once limit reached
  
  @param {string} body
  @param {number} limit
  @api private