src/main/java/com/helger/genericode/Genericode10Helper.java
public static boolean isKeyColumn (@Nonnull final ColumnSet aColumnSet, @Nullable final String sColumnID)
  {
    if (sColumnID != null)
      for (final Key aKey : getAllKeys (aColumnSet))
        for (final KeyColumnRef aColumnRef : aKey.getColumnRef ())
          if (aColumnRef.getRef () instanceof Column)
            if (((Column) aColumnRef.getRef ()).getId ().equals (sColumnID))
              return true;
    return false;
  }
public static boolean isKeyColumn (@Nonnull final ColumnSet aColumnSet, @Nullable final String sColumnID)
  {
    if (sColumnID != null)
      for (final Key aKey : getAllKeys (aColumnSet))
        for (final KeyColumnRef aColumnRef : aKey.getColumnRef ())
          if (aColumnRef.getRef () instanceof Column)
            if (((Column) aColumnRef.getRef ()).getId ().equals (sColumnID))
              return true;
    return false;
  }
Check if the passed column ID is a key column in the specified column set

@param aColumnSet
The column set to scan. May not be <code>null</code>.
@param sColumnID
The column ID to search. May be <code>null</code>.
@return <code>true</code> if the passed column ID is a key column