{
throw new InvalidRequestException("Key may not be empty");
}
if ( !DatabaseDescriptor.getTables().contains(tablename) )
{
throw new TableNotDefinedException("Table " + tablename + " does not exist in this schema.");
}
Table table = Table.open(tablename);
for (String cfName : columnFamilyNames)
{
if (!table.getColumnFamilies().contains(cfName))