t4047.scala:23: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
  a.foo
    ^
t4047.scala:24: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
  a.foo
    ^
t4047.scala:26: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
  b.foo
    ^
t4047.scala:27: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
  b.foo
    ^
Unit: called A.foo
Unit: called B.foo
Unit: called C.foo
Unit: called D.foo
Unit: called D.foo