WordPress at a glance
function is not described

WC_Tax::get_base_tax_rates() public WC 1.0

Get's an array of matching rates for the shop's base country.

{} It's a method of the class: WC_Tax{}

Hooks from the method
Return

Array. Nothing.

Usage

$result = WC_Tax::get_base_tax_rates( $tax_class );
$tax_class(string)
Tax Class.

Code of WC_Tax::get_base_tax_rates() WC 5.3.0

<?php
public static function get_base_tax_rates( $tax_class = '' ) {
	return apply_filters(
		'woocommerce_base_tax_rates',
		self::find_rates(
			array(
				'country'   => WC()->countries->get_base_country(),
				'state'     => WC()->countries->get_base_state(),
				'postcode'  => WC()->countries->get_base_postcode(),
				'city'      => WC()->countries->get_base_city(),
				'tax_class' => $tax_class,
			)
		),
		$tax_class
	);
}