“Gang of Four”, the name commonly applied to the authors of the seminal book “Design Patterns” https://en.m.wikipedia.org/wiki/Design_Patterns https://en.m.wik

“Gang of Four”, the name commonly applied to the authors of the seminal book “Design Patterns” https://en.m.wikipedia.org/wiki/Design_Patterns https://en.m.wikipedia.org/wiki/Design_Patterns