org.apache.flex.compiler.tree.mxml
package.
It contains classes that implement the MXML node interfaces. After the AST for a compilation unit has been built, you should access nodes only through the external interfaces and never through these internal classes. The methods in the interfaces are guaranteed to be safe to call from multiple threads, while the methods in these classes are not.
See the description
of the org.apache.flex.compiler
package for an explanation
of how the compiler code is organized into external and internal packages.