I am getting this error please help with this in java 8

You've received a stream(()) groups of three samples and retain only complete triples. - Eliminate all triples whose average is higher than 30. - Join all the triples again. - Use SampleNormalizer to normalize the values. Unfortunately, due to poor design it returns optional> and is a bit buggy: it may return nulls (empty optionals), which you must eliminate. Samplekormalizer's normalize method accepts a single BigDecimal. - Return a stream= normalizer: \} StreamsBigDecimal> preprocess(StreameBigDecimal> input) \{ input = input filter (bdbd!=null&s bd, compareTo (zER0)>0); input = input. collect(groupingBy (new Atomicinteger(): :getAndincrement, averagingDouble (BigDecimal: :doubleValue))) - values[ [ ) - strean() - filter(avg avg. doubleValue() \&30) - flathap(group Stream. of (group. toArray(new BigDecimat[3]))) - filter(list list. size() = = 3 ) - map(list 1ist, stream(), reduce(BigDecimal.ZERO, BigDecimal: :add). divide(BigDecimal. value0f(3 input = input, map(normalizer: inormalize), filter(Optional: :ispresent).map(Optional: :get); return input; groupingBy(new Atomic [...] ]ement, Collector) input = input.collect (groupingBy(new AtomicInteger()::getAndincrement, averagingDouble(BigDecimal: :doubleValue))) method Collectors. groupingBy(Function super T\#1,? extends K#1>, Supplier M>, Collector ) is not applicable (cannot infer type-variable(s) T\#1, K\#1, D\#1, A\#1, M (actual and formal argument lists differ in length)) method Collectors. groupingBy(Function super T\#2,? extends K\#2>, Collector super T\#2, A\#2, D\#2>) is not applicable (cannot infer type-variable(s) T\#2, K\#2,A\#2,D\#2 (argument mismatch; invalid method reference method getAndIncrement in class AtomicInteger cannot be applied to given types required: no arguments found: T\#2 reason: actual and formal argument lists differ in length)) method Collectors. groupingBy(Function super T\#3,? extends K#3> ) is not applicable (cannot infer type-variable(s) T\#3, K\#3 (actual and formal argument lists differ in length)) where T\#1, K\#1, D\#1, A\#1, M, T\#2, K\#2, A\#2, D\#2, T\#3, K\#3 are type-variables: T\#1 extends Object declared in method groupingBy(Function super T\#1,? extends K\#1>, Supplier , Collector ) K\#1 extends Object declared in method groupingBy(Function super T\#1,? extends K\#1>, Supplier M>, Collector ) D\#1 extends 0bject declared in method groupingBy(Function super T\#1,? extends K\#1>, Supplier , Collector ) A\#1 extends object declared in method groupingBy(Function super T\#1,? extends K\#1>, Supplier , Collector ) M extends Map declared in method groupingBy(Function super T\#1,? extends K\#1>, Supplier , Collector ) T\#2 extends Object declared in method groupingBy(Function super. T\#2,? extends K\#2>, Collector super T\#2, A\#2, D\#2 ) K\#2 extends object declared in method groupingBy(Function super T\#2,? extends K\#2>, Collector super T\#2, A\#2, D\#2>)