/// Subtractss the provided key to the sum of blinding factors.
public BlindSum sub_blinding_factor(BlindingFactor blind)
{
NegativeBlindingFactors.Add(blind);
return(this);
}
/// Adds the provided key to the sum of blinding factors.
public BlindSum add_blinding_factor(BlindingFactor blind)
{
PositiveBlindingFactors.Add(blind);
return(this);
}