Renders chart data in horizontal lines; from left to right it paints:
an optional icon, which is requested by #getIcon()
the data's label, aligned left or right
a colored bar with a size label in or besides it.
Scans a file system in depth-first order and returns a scan result,
which consists of the scan configuration and a tree of Directory instances
and FileInfos that represent the scanned tree.
Returns the current statistics depth that indicates
for how many levels we collect and store the cumulated
statistics: top lists, distributions and types.