ECP is BB testing technique that divide input domain of a
program into classes.Like

1.If I/P condition specifies range, one valid and two
invalid classes are defined
2.If I/P condition requires specific value,one valid and two
invalid classes are defined
3.If I/P condition is member of set,One valid and one
invalid classes are defined
4.If I/P condition is Boolean,One valid and one Invalid
classes are defined.