original_string: protected function assertHeaderValue($value)
      {
          if (!is_string($value) && (!is_array($value) || array_product(array_map('is_string', $value)) === 0)) {
              throw new \InvalidArgumentException("Header value should be a string or an array of strings");
          }
      }
code: protected function assertHeaderValue($value)
      {
          if (!is_string($value) && (!is_array($value) || array_product(array_map('is_string', $value)) === 0)) {
              throw new \InvalidArgumentException("Header value should be a string or an array of strings");
          }
      }
code_tokens: protected function assertHeaderValue ( $ value ) { if ( ! is_string ( $ value ) && ( ! is_array ( $ value ) || array_product ( array_map ( 'is_string' , $ value ) ) === 0 ) ) { throw new \ InvalidArgumentException ( "Header value should be a string or an array of strings" ) ; } }
docstring: Assert that the header value is a string
  
  @param string|string[] $value
  @throws \InvalidArgumentException
docstring_tokens: Assert that the header value is a string