code: function init_block() {
  		var n; // iterates over tree elements
  
  		// Initialize the trees.
  		for (n = 0; n < L_CODES;  n++) {
  			dyn_ltree[n].fc = 0;
  		}
  		for (n = 0; n < D_CODES;  n++) {
  			dyn_dtree[n].fc = 0;
  		}
  		for (n = 0; n < BL_CODES; n++) {
  			bl_tree[n].fc = 0;
  		}
  
  		dyn_ltree[END_BLOCK].fc = 1;
  		opt_len = static_len = 0;
  		last_lit = last_dist = last_flags = 0;
  		flags = 0;
  		flag_bit = 1;
  	}
docs: /* ==========================================================================
  Initialize a new block.