get/set functions for internal array, this._original. something like:
get array(): object[] {
return this._original
}
set array(input: object[]) {
// same as constructor but without reassigning `this._keys`
// should be moved to new function to avoid code duplication
this._original = input.map((x) => Object.assign({}, x))
this._transposed = transpose(this._keys, this._original)
}
get/set functions for internal array,
this._original
. something like: