Constant BIP112_CSV_ACTIVATION_MAINNET 

pub const BIP112_CSV_ACTIVATION_MAINNET: u64 = 419_328; // 419_328u64

BIP112/BIP113: CHECKSEQUENCEVERIFY (CSV) - Mainnet activation height

SCRIPT_VERIFY_CHECKSEQUENCEVERIFY (0x400). Not the same as BIP147 (NULLDUMMY). Reference: Bitcoin Core consensus.nCSVEnabled = 419328 on mainnet.