public XMLSchema getXMLSchemaByTargetNamespace(URI targetNamespace) {
    XMLSchemaInformation info = getByTargetNamespace(targetNamespace);
    if (info == null) {
      return null;
    }

    return info.getSchema();
  }
  public Collection<XMLSchema> getDependingXMLSchemas(URI namespace) {
    Collection<XMLSchema> schemas = new ArrayList<XMLSchema>();

    Collection<XMLSchemaInformation> dependingSchemas = getDependingXMLSchemaInformation(namespace);
    for (XMLSchemaInformation info : dependingSchemas) {
      schemas.add(info.getSchema());
    }
    return schemas;
  }
  public XMLSchema getMaterializedXMLSchemaByTargetNamespace(URI targetNamespace) {
    XMLSchemaInformation info = getByTargetNamespace(targetNamespace);
    if (info == null) {
      return null;
    }

    materializeXMLSchemaInformation(info);
    return info.getSchema();
  }