Biz system Cidentity：BIZ_C
if BIZ_B
Identify the business identity
extend_B_1
extend_A_1
Biz system Bidentity：BIZ_B
common-logic_1
if BIZ_A && BIZ_B
middle station logic finish
middle station logic start
if BIZ_A
common-logic_2
extend_B_2
common-logic_3
Biz system Aidentity：BIZ_A
if BIZ_C
