Builders should include mandatory parameters in their constructor

[bgreen1005]

Builders should include mandatory parameters in their constructor

[jjaquinta]

Adding additional constructors would be fine. But replacing them wouldn't be backward compatible.
What could be done (if it isn't already) is when .build() is called, that it validates that all the mandatory values are present, that all present values are in the correct format, or throw an IllegalArgumentException if not. That way it it is more likely to "fail quickly" if a programmer has a typo.

This is now supported in our current SDK with what @jjaquinta has mentioned.