XmlScriptProducer + availableProperties
ignore scratch
move methods from RuleEngine to Assignments to let Assignments implement
PropertyContainer
methods ruleMock, assignmentMock in TestUtils
let assigments return undefined for not assigned properties
use assignments in xml script producer tests
Let PropertyContainer return Assignments as map
refactor XmlScriptProducerTest: remove duplication extracting methods
organize imports
again
output arbitrary properties
ignores undefined properties
refactor the test again
again