<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def convert_ints_to_bytes(in_ints, num):
 """Convert an integer array into a byte arrays. The number of bytes forming an integer is defined by num :param in_ints: the input integers :param num: the number of bytes per int :return the integer array"""

    out_bytes= b""
    for val in in_ints:
        out_bytes+=struct.pack(mmtf.utils.constants.NUM_DICT[num], val)
    return out_bytes