remove useless function
It has no user left and no purpose in live.
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d3f20770b86a31dba56ae7b252089e12b34702da 0.2.0
c046b083a5e0b21af69027f31cee141800cf894b 0.3.0
9bbcd274689829d9239978236e16610688978233 0.4.0
4ecbaec1d664b1e6f8ebc78292e1ced77a8e69c0 0.4.1
7ef8ab8c6feadb8a9d9e13af144a17cb23e9a38d 0.5
4a5488c01a66be4729252175cea0ea739a88a540 0.6
18a0d96ed559089edf90206c469f3f8c26681c64 0.7
18a0d96ed559089edf90206c469f3f8c26681c64 0.7
1b2757c1bd918509184f6c1d06b2329a847e31b0 0.7