Mastering refactoring - change function declaration, start code

change_function_declaration_start.kt

private fun printInvoiceSheet(invoice: Invoice) {
    printDetails(invoice)
    printInvoiceItemsSection(invoice.items, 22.0)
}

private fun printDetails(invoice: Invoice) {
    val invoiceHeader = "INVOICE N° ${invoice.number}, ${invoice.date}\n\n"
    binding.tvInvoicePreview.text = invoiceHeader
}