// Conceptually, this should be +inf, but 0.0 meets the requirements
// of Simple_spacer and creates fewer cases of 0.0*inf to handle.
blocking_force_ = 0.0;
// Conceptually, this should be +inf, but 0.0 meets the requirements
// of Simple_spacer and creates fewer cases of 0.0*inf to handle.
blocking_force_ = 0.0;