'initialize the best solution with `x`, `f`, and `evals`.
Better solutions have smaller `f`-values.'

def __init__(self, x=None, f=np.inf, evals=None):

    self.x = x
    self.x_geno = None
    self.f = (f if ((f is not None) and (f is not np.nan)) else np.inf)
    self.evals = evals
    self.evalsall = evals
    self.last = BlancClass()
    self.last.x = x
    self.last.f = f
