interface to mark a AstNode as Variable. Typically these are
VariableExpression, FieldNode, PropertyNode and Parameter
- Jochen Theodorou
the type before wrapping primitives type of the variable
expression used to initialize the variable or null of there
is no initialization.
returns true if there is an initialization expression
returns true if this variable is used in a static context.
A static context is any static initializer block, when this variable
is declared as static or when this variable is used in a static method