if(v == null) {
SchemaPath column = SchemaPath.getSimplePath(familyName);
MaterializedField field = MaterializedField.create(column, COLUMN_FAMILY_TYPE);
v = outputMutator.addField(field, MapVector.class);
if (allocateOnCreate) {
v.allocateNew();
}
getColumns().add(column);
familyVectorMap.put(familyName, v);
}
return v;