c1 = 7S
c2 = JS
c3 = AC
c4 = AD
c5 = JS

c1.sameSuitAs(c1) = true
c1.sameSuitAs(c2) = true
c3.sameSuitAs(c4) = false
c2.sameSuitAs(c5) = true
c2.sameSuitAs(null) = false

c1.equals(c1) = true
c1.equals(c2) = false
c3.equals(c4) = false
c2.equals(c5) = true
c2.equals(null) = false