test/model/default/classes/first.yml

parameters:
  _param:
    some: param
    colour: red
  lab:
    name: test
    label: first
  colour:
    escaped: \${_param:colour}
    doubleescaped: \\${_param:colour}
    unescaped: ${_param:colour}
  colours:
    red:
      name: red
    blue:
      name: blue
  one:
    a: 1
    b: 2
  two:
    c: 3
    d: 4
  three:
    e: 5
  list_to_override:
  - one
  - two
  dict_to_override:
   one: 1
   two: 2