A compound symbol is a symbol that uses other symbols
(called subsymbols) as graphical elements.
Before you can add a compound symbol to your project,
you need to have the compiled classes of its subsymbols available
in the class path of the Symbol Compiler environment. If you plan
to have a compound symbol and its subsymbols in the same project,
you need to add the subsymbols first and execute the Generate and Compile action before adding your
compound symbol.