package com.atlassian.dbexporter;
   
   import static com.google.common.base.Preconditions.checkNotNull;
   
   public final class ForeignKey {
       private final String fromTable;
       private final String fromField;
       private final String toTable;
       private final String toField;
  
      public ForeignKey(String fromTable, String fromField, String toTable, String toField) {
          this.fromTable = checkNotNull(fromTable);
          this.fromField = checkNotNull(fromField);
          this.toTable = checkNotNull(toTable);
          this.toField = checkNotNull(toField);
      }
  
      public String getFromTable() {
          return fromTable;
      }
  
      public String getFromField() {
          return fromField;
      }
  
      public String getToTable() {
          return toTable;
      }
  
      public String getToField() {
          return toField;
      }
  }