public static TableName valueOf(ByteBuffer namespace, ByteBuffer qualifier) {
    if (namespace == null || namespace.remaining() < 1) {
      return createTableNameIfNecessary(ByteBuffer.wrap(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME),
        qualifier);
    }

    return createTableNameIfNecessary(namespace, qualifier);
  }
Construct a TableName
@throws IllegalArgumentException if fullName equals old root or old meta. Some code depends on
                                 this.
hbase-common/src/main/java/org/apache/hadoop/hbase/TableName.java