CLUSTER
chrM:307	0	AGCGGGGA	130     #--> Select, first line sorted by col3, col2, col4(rev sort)    # Line1
chrM:307	0	AGCGGGGA	129     #--> Select line with similar UMI  (NO mismatch)                # Line6
chrM:307	0	AGCGGGGA	129     #--> Select line with similar UMI  (NO mismatch)                # Line7
CLUSTER
chrM:307	0	TCAAAATG	130     #--> Now selected, Second line sorted by col3, col2, col4(rev sort)  #Line2 # NO similar UMI, 1 line cluster
CLUSTER
chrM:307	0	TCACGGTG	130     #--> Now selected, Third line sorted by col3, col2, col4(rev sort)  # Line3
chrM:307	0	TCAGGGAG	130     #--> Select line with similar UMI  (Two mismatch with line3 UMI)    # Line4
chrM:307	2	TCAGGGTG	130     #--> Select line with similar UMI  (One mismatch with line3 UMI)    # Line5
chrM:307	2	TCAGGGTG	129     #--> Select line with similar UMI  (One mismatch with line3 UMI)    # Line9
chrM:307	1	TCAGGGTG	106     #--> Select line with similar UMI  (One mismatch with line3 UMI)    # Line10
CLUSTER
chrM:307	0	TCAGCCTG	129     #--> Now selected, line#8 sorted by col3, col2, col4(rev sort)      #Line8, make single line cluster
CLUSTER
....and so on for next chr positions...