var:  &var var-value
scalar: *var
list: [ *var ]
list_in_list: [[ *var ]]
map_in_list: [ { key: *var } ]
embedded_mapping: { key: *var }
map: { key: *var }
list_in_map: { key: [*var] }
map_in_map: { foo: { bar: *var } }