Grouped fields added (for output polarization)

              explicitInclusion=false, units='', explanation='', extras={}) {

    super(wrapper, name, text, required, explicitInclusion, explanation)

    // Check if the field is multiple (num > 1), it is composed by several input field

    if (datatype instanceof Array) this.datatypes = datatype; else this.datatypes = [datatype]

    this.extras = extras

    this.HTMLFieldNames = []

    this.type = type

    this.numRows = 1

    this.numCols = undefined

    if (type.includes(':')){

      let a = type.split(':')

      this.type = a[0]

      if (a[1].includes('x')) {

        const [rows, cols] = a[1].split('x').map(Number)

        this.numRows = rows

        this.numCols = cols

        this.num = rows * cols

      } else {

        this.num = parseInt(a[1])

      }

      if (a.length === 3) this.HTMLFieldNames = a[2].split(',')

    }

    if (this.HTMLFieldNames.length === 0) {

    if (datatype instanceof Array) this.datatypes = datatype

    else this.datatypes = Array(this.num).fill(datatype)

    if (this.numCols) {

      this.#createGroupedFields(units)

    } else if (this.HTMLFieldNames.length === 0) {

      this.#createUnnamedFields(units)

    } else {

      this.#createNamedFields(units)

    }

  }

  /**

   * A helper function creating NxM fields grouped into rows, each row with a subtitle

   * @param units {Array<string>} units per field

   */

  #createGroupedFields(units) {

    const valueInputBox = this.wrapper.querySelector('.value-box')

    const unitsBox = this.wrapper.querySelector('.units-box')

    for (let row = 0; row < this.numRows; row++) {

      let rowDiv = document.createElement('div')

      rowDiv.className = 'named-subfield'

      let subtitle = document.createElement('span')

      subtitle.className = 'named-subfield-subtitle'

      subtitle.innerHTML = this.HTMLFieldNames[row] ?? ''

      rowDiv.appendChild(subtitle)

      let fieldsDiv = document.createElement('div')

      fieldsDiv.className = 'named-subfield-fields'

      for (let col = 0; col < this.numCols; col++) {

        const idx = row * this.numCols + col

        let field = document.createElement('input')

        field.type = 'text'

        field.style.width = (100 / this.numCols) + '%'

        fieldsDiv.appendChild(field)

        this.HTMLFields.push(field)

        let unitSpan = document.createElement('span')

        unitSpan.innerHTML = units?.[idx] ?? ''

      }

      rowDiv.appendChild(fieldsDiv)

      valueInputBox.appendChild(rowDiv)

    }

  }

  /**

   * Returns value/values of the field

   * @returns {*[]|*}

    if (!(value instanceof Array)) value = [value]

    if (value.length !== this.num) throw(`Cannot set value to ${this.name}`)

    for (let i = 0; i < this.num; i++)

      this.HTMLFields[i].value = value[i]

      if (value[i] !== undefined) this.HTMLFields[i].value = value[i]

  }

  // clearValue() {

  //   for (let i = 0; i < this.num; i++)