public SchemaImpl createSchema(String targetNamespace,Locator location,boolean elementFormDefault,boolean attributeFormDefault){
  SchemaImpl obj=(SchemaImpl)schemas.get(targetNamespace);
  if (obj == null) {
    obj=new SchemaImpl(this,location,targetNamespace,elementFormDefault,attributeFormDefault);
    schemas.put(targetNamespace,obj);
    schemas2.add(obj);
  }
  return obj;
}

public SchemaImpl createSchema ( String targetNamespace , Locator location , boolean elementFormDefault , boolean attributeFormDefault ) { SchemaImpl obj = ( SchemaImpl ) schemas . get ( targetNamespace ) ; if ( obj == null ) { obj = new SchemaImpl ( this , location , targetNamespace , elementFormDefault , attributeFormDefault ) ; schemas . put ( targetNamespace , obj ) ; schemas2 . add ( obj ) ; } return obj ; }
gets a reference to the existing schema or creates a new one if none exists yet .
