var target = "Homer";
target.ShouldBe("Bart");

target
    should be
"Bart"
    but was
"Homer"
    difference
Difference     |  |    |    |    |    |   
               | \|/  \|/  \|/  \|/  \|/  
Index          | 0    1    2    3    4    
Expected Value | B    a    r    t         
Actual Value   | H    o    m    e    r    
Expected Code  | 66   97   114  116       
Actual Code    | 72   111  109  101  114

var target = "Bart";
target.ShouldNotBe("Bart");

target
    should not be
"Bart"
    but was