If you're not so biased towards Djokovic you could have read in the OP his comments about him haven't been tested for blood 6/7 months and the tests had been regularly taken 2/3 years back. He also said the more blood tests and urine the better for the sport.
You may consider also that English is not his mother tongue and refrain himself from more profound discussions because it may be difficult to him.
Oh please. He said drug testing in tennis is 'really good'.
Comparing those comments to Federer and Murray, who actually came straight out and said that the current system isn't good enough, is ridiculous. Yet you call me biased? Irony.