invitation_params = {
    team_id: 1,
    emails: ["beyonce@email.com", "kelly@email.com", "michelle@email.com"]
}

def invite(invitation_params)
  invitees_emails = remove_existing_emails(invitation_params)
  invitees_emails.each do |email|
    send_invite(email) # This method is not shown.
  end
end

def remove_existing_emails(invitation_params)
  existing_emails_on_team = grab_emails_from_team(invitation_params["team_id"])
  email_params = invitation_params["emails"].map(&:downcase)
  email_params - existing_emails_on_team
end

def grab_emails_from_team(team_id)
  user_ids = User.where(team_id: team_id).pluck(:email)
end