Interface Hashable

Hashable mimics Java native Object.hashCode implementation, which benefits hash tables such as those provided by HashMap The general contract of hashCode() method is:

• Multiple invocations of hashCode() should return the same integer value, unless the object property is modified that is being used in the equals() method.
• An object hash code value can change in multiple executions of the same application.
• If two objects are equal according to equals() method, then their hash code must be same.
• If two objects are unequal according to equals() method, their hash code are not required to be different.
• Their hash code value may or may-not be equal.

The implementation of equals() and hashCode() should follow these rules:

• If o1.equals(o2), then o1.hashCode() == o2.hashCode() should always be true.
• If o1.hashCode() == o2.hashCode is true, it doesn’t mean that o1.equals(o2) will be true.