code: public static TableRef valueOf(String tableName) {
          if (tableName == null) {
              throw new IllegalArgumentException("TableName cannot be null.");
          }
          String[] components = tableName.split("\\.");
          return TableRef.valueOf(components);
      }
docs: Creates an instance from a table name
  <p/>
  <p>The  table name must have the format [&LT;catalog&GT;.][&LT;schema&GT;.]&LT;tablename&GT;.
  if the catalog or schema component is empty, the catalog or schema will be set to
  <code>null</code>.</p>
  
  @param tableName the table name
  @return a <code>TableRef</code> for the table identified by the specified table name.
  @throws IllegalArgumentException if the tableName parameter is null