WordPress/Sniffs/NamingConventions/ValidVariableNameSniff.php
protected function mergeWhiteList() {
		if ( $this->customPropertiesWhitelist !== $this->addedCustomProperties['properties'] ) {
			// Fix property potentially passed as comma-delimited string.
			$customProperties = Sniff::merge_custom_array( $this->customPropertiesWhitelist, array(), false );

			$this->whitelisted_mixed_case_member_var_names = Sniff::merge_custom_array(
				$customProperties,
				$this->whitelisted_mixed_case_member_var_names
			);

			$this->addedCustomProperties['properties'] = $this->customPropertiesWhitelist;
		}
	}
protected function mergeWhiteList() {
		if ( $this->customPropertiesWhitelist !== $this->addedCustomProperties['properties'] ) {
			// Fix property potentially passed as comma-delimited string.
			$customProperties = Sniff::merge_custom_array( $this->customPropertiesWhitelist, array(), false );

			$this->whitelisted_mixed_case_member_var_names = Sniff::merge_custom_array(
				$customProperties,
				$this->whitelisted_mixed_case_member_var_names
			);

			$this->addedCustomProperties['properties'] = $this->customPropertiesWhitelist;
		}
	}
Merge a custom whitelist provided via a custom ruleset with the predefined whitelist,
if we haven't already.

@since 0.10.0
@since 2.0.0  Removed unused $phpcs_file parameter.

@return void