in lib/pry/byebug/breakpoints.rb [50:58]
def add_method(method, expression = nil)
validate_expression expression
owner, name = method.split(/[\.
byebug_bp = ::Byebug::Breakpoint.add(owner, name.to_sym, expression)
bp = MethodBreakpoint.new byebug_bp, method
breakpoints << bp
bp
end