def correct_spacer(read, umi, umi_pos, spacer_seq):
    """
    (str, str, int, str) -> bool
    :param reads: Read sequence
    :param umis: Umi sequence
    :param umi_pos: Expected position 0-based on umi in read
    :spacer_seq: Spacer sequence
    
    Return False if umi not in read or spacer in sequence but not at expected position and return True otherwise 
    """
    Correct = True
    if umi.upper() not in read.upper():
        Correct = False
    else:
        read = read[umi_pos + len(umi):]
        if not read.upper().startswith(spacer_seq.upper()):
            Correct = False
    return Correct
