azure-storage-common/src/Common/Internal/Utilities.php
public static function tryGetValueInsensitive($key, $haystack, $default = null)
    {
        $array = array_change_key_case($haystack);
        return Utilities::tryGetValue($array, strtolower($key), $default);
    }
public static function tryGetValueInsensitive($key, $haystack, $default = null)
    {
        $array = array_change_key_case($haystack);
        return Utilities::tryGetValue($array, strtolower($key), $default);
    }
Returns the specified value of the $key passed from $array and in case that
this $key doesn't exist, the default value is returned. The key matching is
done in a case insensitive manner.

@param string $key      The array key.
@param array  $haystack The array to be used.
@param mixed  $default  The value to return if $key is not found in $array.

@return mixed