This module allows to specify 'virtual columns' in DBIx::Class schema
classes. Virtual columns behave almost like regular columns but are not
stored in the database. They may be used to store temporary information
in the DBIx::Class::Row object and without introducting an additional
interface.

Most DBIx::Class methods like "set_column", "set_columns", "get_column",
"get_columns", "column_info", ... will work with regular as well as
virtual columns.
