[MAP] len 5
key[0]: [STR] len 1 value 'a'
val[0]: [STR] len 1 value 'A'
key[1]: [STR] len 1 value 'b'
val[1]: [STR] len 1 value 'B'
key[2]: [STR] len 1 value 'c'
val[2]: [STR] len 1 value 'C'
key[3]: [STR] len 1 value 'd'
val[3]: [STR] len 1 value 'D'
key[4]: [STR] len 1 value 'e'
val[4]: [STR] len 1 value 'E'