veDOP is non-transferable token that can only be obtained through locking DOP.
User determines own lock-up length, the maximum being up to 4 years. 1 DOP locked for 4 years provides 1 veDOP.
Over time veDOP balance is decreasing as locked DOP gets closer to the unlock date.
For example, when a user locks 1,000 DOP for 4 years, veDOP balance will be 1000. After 2 years pass, veDOP balance will become 500 veDOP and 0 veDOP after 4 years.