１．Purpose
・ Define the description method of Event and function flow.

２．Directories and files

-+- index.js
 |
 +- app
 |  |- ActionWidget.js
 |
 +- routes
    |- client_invoice.js
    |- client_to_supplier.js
    |- supplier_message.js
    |- invoice_sub.js
    |- database.js

３．Example
(1) [ Make Payment ]

button:{
  [ Make Payment ]
}
flow:{
  (e) evt_handleInvoiceMakePayment =function: this.DOM.modal.body.classList.add   
     === dialogue window =button: [ Make payment ]
  (e) evt_handleModalSubmitClick =url: /api/invoice/makePayment
  >>> {/api/invoice}/makePayment =function: to_supplier.makePayment
     --> supplier_makePayment () {
        ${supplier_host} = sub.getSupplierHost 
           --> api_setMakePayment =function: db.query
        =url: ${supplier_host}/api/message/supplierToMakePayment
     }
  >>> {/api/message}/supplierToMakePayment =function: sub.setMakePayment
     --> api_setMakePayment =function: db.update
}
files:{
  evt_handleInvoiceMakePayment @ ./app/ActionWidget.js
  evt_handleModalSubmitClick   @ ./app/ActionWidget.js
  /api/invoice/makePayment     @ ./app/ActionWidget.js
  {/api/invoice}               @ ./index.js
  /api/invoice                 = require('./client_invoice.js')
  /makePayment                 @ ./routes/client_invoice.js
  supplier_makePayment         @ ./routes/client_to_supplier.js
  ${/api/message}              @ ./index.js
  /api/message                 @ require('./supplier_message.js')
  supplierToMakePayment        @ ./routes/supplier_message.js
  sub                          = require("./invoice_sub.js")
  api_getSupplierHost          @ ./routes/invoice_sub.js
  api_setMakePayment           @ ./routes/invoice_sub.js
  db                           = require("./database.js")
  db_query                     @ ./routes/database.js
  db_update                    @ ./routes/database.js
}

４．Description method
making…