public ExtensionQuery(String extensionPointName,String attributeName){
  Preconditions.checkArgument(extensionPointName.contains("."),"expected fully-qualified extension point");
  this.pluginId=null;
  this.extensionPointName=extensionPointName;
  this.attributeName=attributeName;
}

public ExtensionQuery ( String extensionPointName , String attributeName ) { Preconditions . checkArgument ( extensionPointName . contains ( "." ) , "expected fully-qualified extension point" ) ; this . pluginId = null ; this . extensionPointName = extensionPointName ; this . attributeName = attributeName ; }
create a new instance .
