A definition representing an
interface declaration.
An IInterfaceDefinitionIInterfaceNode.
For example, the interface declaration
public class I2 extends I1 { } creates an interface definition whose base name is
"I2", whose namespace reference is to the
public namespace, and whose type reference is
null. It has an
IReference named "I1" to the interface that it extends.
An interface definition is contained within a file scope or a package scope, and contains an interface scope. The members of the interface are represented by definitions in the interface scope.