src/RequestTrait.php
private function assertHeaders(array $headers)
    {
        foreach ($headers as $name => $headerValues) {
            HeaderSecurity::assertValidName($name);
            array_walk($headerValues, __NAMESPACE__ . '\HeaderSecurity::assertValid');
        }
    }
private function assertHeaders(array $headers)
    {
        foreach ($headers as $name => $headerValues) {
            HeaderSecurity::assertValidName($name);
            array_walk($headerValues, __NAMESPACE__ . '\HeaderSecurity::assertValid');
        }
    }
private function assertHeaders ( array $ headers ) { foreach ( $ headers as $ name => $ headerValues ) { HeaderSecurity :: assertValidName ( $ name ) ; array_walk ( $ headerValues , __NAMESPACE__ . '\HeaderSecurity::assertValid' ) ; } }
Ensure header names and values are valid.

@param array $headers
@throws InvalidArgumentException
Ensure header names and values are valid .