code: public boolean insertGroup(String name)
  	{
  		if (isGroupExist(name))
  		{
  			throw new SystemException(String.format("Group '%s' already exist.", name));
  		}
  
  		return allGroups.add(name);
  	}
docs: <p>insertGroup.</p>
  
  @param name a {@link java.lang.String} object.
  @return a boolean.