The above answer may be correct, however, it is already a predefined class. In which, the error I get from this code is as follows:

"StaticSet.java:$59$: error: cannot find symbol

if $($predicate$.$test$($item$))\{$

$^$

symbol: method test$($T$)$

location: variable predicate of type Predicate

where T is a type$-$variable:

T extends Object declared in class StaticSet

StaticSet.java:$60$: error: cannot find symbol

newSet.add$($item$)$;

$^$

symbol: variable newSet

location: class StaticSet

where T is a type$-$variable:

T extends Object declared in class StaticSet

StaticSet.java:$63$: error: cannot find symbol

return new StaticSetnewSet$)$;

$^$

symbol: variable newSet

location: class StaticSet

where T is a type$-$variable:

T extends Object declared in class StaticSet

StaticSet.java:$78$: error: cannot find symbol

HashSet newSet $=$ new HashSet;

$^$

symbol: class r

location: class StaticSet

where T is a type$-$variable:

T extends Object declared in class StaticSet

StaticSet.java:$80$: error: cannot find symbol

newSet.add$($function$.$apply$($item$))$;

$^$

symbol: variable function

location: class StaticSet

where T is a type$-$variable:

T extends Object declared in class StaticSet

$5$ errors"

Could this code fit into this? Where it says $"//$Your code here..." please write and explain how this could work with the code provided for StaticSet.java class:

StaticSet.java

import java.util.$*$;

import java.io$.$PrintWriter;

public class StaticSet $\{$

private HashSet set $=$ new HashSet$()$;

$//$ Constructs an empty StaticSet

public StaticSet$()\{$

$\}$

$//$ Constructs the StaticSet by adding all ArrayList items

public StaticSet$($ArrayList items$)\{$

for $($T item : items$)\{$

set.add$($item$)$;

$\}$

$\}$

$//$ Constructs the StaticSet by copying itemsToCopy's items

public StaticSet$($HashSet itemsToCopy$)\{$

this.set $=$ new HashSet$($itemsToCopy$)$;

$\}$

public boolean contains$($T item$)\{$

return true $==$ set.contains$($item$)$;

$\}$

public int getSize$()\{$

return set.size$()$;

$\}$

public void print$($PrintWriter output, String separator, String prefix, String suffix$)\{$

output.write$($prefix$)$;

boolean firstItem $=$ true;

for $($T item : set$)\{$

if $($firstItem$)\{$

output.write$($item$.$toString$())$;

firstItem $=$ false;

$\}$ else $\{$

output.write$($separator $+$ item.toString$())$;

$\}$

$\}$

output.write$($suffix$)$;

$\}$

$//$ Returns a StaticSet containing each element from this set that is not

$//$ in otherSet.

public StaticSet difference$($StaticSet otherSet$)\{$

$//$ Your code here $($remove placeholder line below$)$

return new StaticSet$()$;

$\}$

$//$ Returns a StaticSet containing each element from this set that

$//$ satisfies the predicate.

$//-$ If predicate$($item$)$ returns true $(1),$ item satisfies the predicate.

$//-$ If predicate$($item$)$ returns false $(0),$ item does not satisfy the predicate.

public StaticSet filter$($Predicate predicate$)\{$

$//$ Your code here $($remove placeholder line below$)$

return new StaticSet$()$;

$\}$

$//$ Returns a StaticSet containing each element from this set that is also

$//$ in otherSet.

public StaticSet intersection$($StaticSet otherSet$)\{$

$//$ Your code here $($remove placeholder line below$)$

return new StaticSet$()$;

$\}$

$//$ Calls mapMethod$($item$)$ for each item in this set and adds the returned

$//$ item to a StaticSet. After mapMethod has been called for each item

$//$ in this set, the StaticSet object is returned.

public StaticSet map$($Predicate mapMethod$)\{$

$//$ Your code here $($remove placeholder line below$)$

return new StaticSet$()$;

$\}$

$//$ Returns a StaticSet containing every element from this set and every

$//$ element from otherSet.

public StaticSet union$($StaticSet otherSet$)\{$

$//$ Your code here $($remove placeholder line below$)$

return new StaticSet$()$;

$\}$

$\}$

Thank you.