def METHOD_NAME (self, pcap_name):
    """
    Checks if a certain .pcap file has been added into the yaml object.
    :parameters:  
        pcap_name : str
            the name of the pcap file to be searched
    :return: 
        + The index of the pcap file (as int) if exists
        + -1 if not exists.
    """
    comp_pcap = pcap_name if pcap_name.startswith(self.trex_files_path) else (self.trex_files_path + pcap_name)
    for idx, pcap in enumerate(self.yaml_obj[0]['cap_info']):
        print (pcap['name'] == comp_pcap)
        if pcap['name'] == comp_pcap:
            return idx
    # pcap file wasn't found
    return -1