•Juno
constructor creates a ShellCommandTable (Juno.java line 52)
•ShellCommandTable.java
–declare
and initialize a TreeMap (line 23)
–constructor
(line 31) invokes fillTable (line 69)
–fillTable
creates one of each concrete ShellCommand objects, invokes install
(line 61) to put it in the table
–client
(a Shell) invokes lookup (43), which wraps Map get method (and does the
cast)