# About this kata
This kata refers to the book Effective Java by Joshua Bloch.
It addresses

Item 1: Consider static factory methods instead of constructors.

# Problem description
Provid a class that 
Use factory method to construct an instance by a good understandable name.
The instance shall be only created when there is no existing one.

advantages of factory method usage instead of constructors:
# Unlike constructors the method has a meaningful name.
# Unlike constructors it is not required to create a new object each time they are invoked.
# Unlike constructors it can return an object of any subtype of their return type.
# The returned object can vary from call to call as function of the input parameters.
# The class of the returned object need not exist when the class containing the method is written. ????


# Clues