Histograms failed to satisfy

src/main/scala/leon/refactor/RepairCostModel.scala

src/main/scala/leon/synthesis/CostModel.scala

src/main/scala/leon/synthesis/Histogram.scala

src/main/scala/leon/synthesis/PartialSolution.scala

src/main/scala/leon/synthesis/SynthesisOptions.scala

src/main/scala/leon/synthesis/SynthesisPhase.scala

src/main/scala/leon/synthesis/graph/DotGenerator.scala

src/main/scala/leon/synthesis/graph/Graph.scala

src/main/scala/leon/synthesis/graph/Search.scala