This class implements the interface described in Section 46, “
class ColumnLayout: Column layout
controller” for the split-year case,
where each effort key gets its own column in the main
# - - - - - c l a s s S p l i t L a y o u t class SplitLayout(ColumnLayout): '''Column dispatcher for split years (one column per effort). State/Invariants: ._keyList: [ a list of the unique effort-keys in self, in ascending order ] ._keyColxMap: [ a dictionary whose keys are the effort-keys in self, and each related value is the logical column number in which that effort is displayed ] '''