code: public synchronized String getAttribute(String key, String defaultValue)
  	{
  		if(attributes.containsKey(key))
  		{
  			return attributes.get(key).toString();
  		}
  		return defaultValue;
  	}
docs: /* (non-Javadoc)
  @see org.overture.ide.internal.core.resources.IOptionGroup#getAttribute(java.lang.String, java.lang.String)