code: public Member addMember(Object projectIdOrPath, Integer userId, Integer accessLevel) throws GitLabApiException {
          return (addMember(projectIdOrPath, userId, accessLevel, null));
      }
docs: Adds a user to a project team. This is an idempotent method and can be called multiple times
  with the same parameters. Adding team membership to a user that is already a member does not
  affect the existing membership.
  
  <pre><code>POST /projects/:id/members</code></pre>
  
  @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
  @param userId the user ID of the member to add, required
  @param accessLevel the access level for the new member, required
  @return the added member
  @throws GitLabApiException if any exception occurs