public class HBaseStorage.ColumnInfo
Class to encapsulate logic around which column names were specified in each
position of the column list. Users can specify columns names in one of 4
ways: 'Foo:', 'Foo:*', 'Foo:bar*' or 'Foo:bar'. The first 3 result in a
Map being added to the tuple, while the last results in a scalar. The 3rd
form results in a prefix-filtered Map.