question: @ Override public Table summary ( ) { Table table = Table . create ( "Column: " + name ( ) ) ; CategoryColumn measure = CategoryColumn . create ( "Measure" ) ; CategoryColumn value = CategoryColumn . create ( "Value" ) ; table . addColumn ( measure ) ; table . addColumn ( value ) ; measure . add ( "Count" ) ; value . add ( String . valueOf ( size ( ) ) ) ; measure . add ( "Missing" ) ; value . add ( String . valueOf ( countMissing ( ) ) ) ; measure . add ( "Earliest" ) ; value . add ( String . valueOf ( min ( ) ) ) ; measure . add ( "Latest" ) ; value . add ( String . valueOf ( max ( ) ) ) ; return table ; }
target:  Returns a table of dates and the number of observations of those dates