def has_header(headers, name):
 name = name.lower()
 for (header, value) in headers:
  if (header.lower() == name):
   return True
 return False

def has_header ( headers , name ) : name = name . lower ( ) for ( header , value ) in headers : if ( header . lower ( ) == name ) : return True return False
is header named name present in headers? .