def createLabelDict_addLabel2df(feats_df):
    """
    Make dictionary associating IDs of signals to the signal's label.
    
    Args: 
        feats_df (dataframe): dataframe that store features.
        
    Returns:
        label_dict: dictionary with labels associated with IDs of signals.
    """
    feats_df_unique = feats_df.drop_duplicates(subset=['Id'])
    label_dict = dict(zip(feats_df_unique.Id, feats_df_unique.label))
    return label_dict