How to use the blessed-contrib.log function in blessed-contrib

columnWidth: [12, 8, 12, 12, 12, 8, 12, 12, 8, 8, 8, 8],  // in chars
  })
  ui.trade_table = contrib.table({
    keys: true,
    fg: 'yellow',
    interactive: false,
    label: 'Trade Buckets',
    width: '48%',
    height: '82%',
    top: '16%',
    left: '50%',
    border: {type: "line", fg: "yellow"},
    columnSpacing: 4, //in chars
    columnWidth: [4, 12, 12, 4, 17], /*in chars*/
  })
  ui.gdax_log = contrib.log({
    fg: "yellow",
    selectedFg: "yellow",
    label: 'GDAX Log',
    left: '2%',
    top: '16%',
    width: '46%',
    height: '28%',
    border: {type: "line", fg: "yellow"}
  })
  ui.sys_log = contrib.log({
    fg: "yellow",
    selectedFg: "yellow",
    label: 'System Log',
    left: '2%',
    top: '47%',
    width: '46%',

const backendCompilerWindow = screenGrid.set(0, 0, 1, 1, Log, {
  fg: 'green',
  label: ' Backend Server Compiler ',
});

const linterWindow = screenGrid.set(0, 1, 2, 2, Log, {
  fg: 'blue',
  label: ' Linter ',
});

const backendServerWindow = screenGrid.set(2, 0, 2, 2, Log, {
  fg: 'green',
  label: ' Backend Server (debugger: chrome://inspect/#devices) ',
});

const frontendWindow = screenGrid.set(1, 0, 1, 1, Log, {
  fg: 'cyan',
  label: ' Frontend Server (http://localhost:8080/) ',
});

screen.render();

writeToWindow(frontendWindow, 'npm', ['run', 'dev:frontend']);
writeToWindow(backendCompilerWindow, 'npm', ['run', 'dev:backend:es6compiler']);
writeToWindow(linterWindow, 'npm', ['run', 'dev:linter:ci']);
setTimeout(() => {
  writeToWindow(backendServerWindow, 'npm', ['run', 'dev:backend:server']);
}, 5000);


// private

private createLog() {
    const logBox = blessed.box({ top: '100%-6', height: 6, width: '100%' })
    this.log = contrib.log({
      border: { type: 'line', fg: 'cyan' },
      fg: 'green',
      height: 6,
      label: 'Logs',
      width: '100%',
    })
    logBox.append(this.log)
    this.screen.append(logBox)
  }
}

left: '50%',
    border: {type: "line", fg: "yellow"},
    columnSpacing: 4, //in chars
    columnWidth: [4, 12, 12, 4, 17], /*in chars*/
  })
  ui.gdax_log = contrib.log({
    fg: "yellow",
    selectedFg: "yellow",
    label: 'GDAX Log',
    left: '2%',
    top: '16%',
    width: '46%',
    height: '28%',
    border: {type: "line", fg: "yellow"}
  })
  ui.sys_log = contrib.log({
    fg: "yellow",
    selectedFg: "yellow",
    label: 'System Log',
    left: '2%',
    top: '47%',
    width: '46%',
    height: '51%',
    border: {type: "line", fg: "yellow"}
  })

  screen.append(ui.overview_table)
  screen.append(ui.trade_table)
  screen.append(ui.gdax_log)
  screen.append(ui.sys_log)

  setInterval( () => {

const blessed = require('blessed');
const Grid = require('blessed-contrib').grid;
const Log = require('blessed-contrib').log;
const spawn = require('child_process').spawn;

const screen = blessed.screen();
const screenGrid = new Grid({ rows: 4, cols: 2, screen: screen });

const backendCompilerWindow = screenGrid.set(0, 0, 1, 1, Log, {
  fg: 'green',
  label: ' Backend Server Compiler ',
});

const linterWindow = screenGrid.set(0, 1, 2, 2, Log, {
  fg: 'blue',
  label: ' Linter ',
});

const backendServerWindow = screenGrid.set(2, 0, 2, 2, Log, {
  fg: 'green',
  label: ' Backend Server (debugger: chrome://inspect/#devices) ',
});

const frontendWindow = screenGrid.set(1, 0, 1, 1, Log, {
  fg: 'cyan',