buildColumnVisibility() {
    if (this._columnVisibility) {
      return this._columnVisibility;
    }
    this._columnVisibility = this.columnSchema.map((column) =>
      Object.assign({}, column, {
        visible: this.isColumnVisible(column.id),
      }),
    );
  }
Builds an array of columns and sets their `visible` property to the
current column's visibility status. The array is stored in
`_columnVisibility` property which will be the true reference to
which columns are visible and which are not at the moment.

@method buildColumnVisibility