in plugin/src/main/groovy/grails/plugins/redis/ast/AbstractMemoizeASTTransformation.groovy [263:270]
protected static ClosureExpression makeClosureExpression(MethodNode methodNode) {
ClosureExpression closureExpression = new ClosureExpression(
[] as Parameter[],
new BlockStatement(methodNode.code.statements as Statement[], new VariableScope())
)
closureExpression.variableScope = new VariableScope()
closureExpression
}