M0 [-d] [classname.]methodname[(signature)]

Set a breakpoint at the first executable line of 'classname.methodname'. 

if 'classname' is not specified, the breakpoint is set on the current debugged class
if 'signature' is not specified and there is only a method named 'methodname', the breakpoint is set on that method
'signature' is a comma separated list of class names or primitive types names,
e.g. (java.lang.String,int,java.awt.Rectangle,boolean) 

[-d: disable the breakpoint]