== Reflexive / null ==
p.equals(p)    = true
p.equals(null) = false

== Symmetry broken by instanceof + extra field ==
plain.equals(red) = true
red.equals(plain) = false
List.of(plain).contains(red) = false
List.of(red).contains(plain) = true

== Transitivity broken by the lenient fix ==
r.equals(plain) = true
plain.equals(b) = true
r.equals(b)     = false

== Consistency broken by a changing equals() ==
f.equals(f2) x4 = true false true false