A compilation unit node containing every AST node that can be a child of a regular compilation unit (that is, all nodes except those exclusively for module or package descriptors).

If you’re looking at its source code: This is not how you should write your nodes. This node’s original purpose was to test CeylonExpressionTransformer: If you read the source file, everything between the BEGIN and END comments is (trimmed) the exact output of completeCompilationUnit.transform(CeylonExpressionTransformer()). For this reason, it is very verbose, using no utility functions, but only occasionally omitting defaulted arguments.

Its main use is to test ceylon.ast transformers and consumers that need to be able to handle every kind of node. Of course, it doesn’t contain each possible configuration of every node type (there is, for example, no else if).