Introduce BigDecimalTwo Refaster rule

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/BigDecimalRules.java

@@ -38,6 +38,19 @@ BigDecimal after() {
     }
   }
 
+  /** Prefer using the constant {@link BigDecimal#TWO} when possible. */
+  static final class BigDecimalTwo {
+    @BeforeTemplate
+    BigDecimal before() {
+      return Refaster.anyOf(BigDecimal.valueOf(2), new BigDecimal("2"));
+    }
+
+    @AfterTemplate
+    BigDecimal after() {
+      return BigDecimal.TWO;
+    }
+  }
+
   /** Prefer using the constant {@link BigDecimal#TEN} when possible. */
   static final class BigDecimalTen {
     @BeforeTemplate

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/BigDecimalRulesTestInput.java

@@ -13,6 +13,10 @@ ImmutableSet<BigDecimal> testBigDecimalOne() {
     return ImmutableSet.of(BigDecimal.valueOf(1), BigDecimal.valueOf(1L), new BigDecimal("1"));
   }
 
+  ImmutableSet<BigDecimal> testBigDecimalTwo() {
+    return ImmutableSet.of(BigDecimal.valueOf(2), BigDecimal.valueOf(2L), new BigDecimal("2"));
+  }
+
   ImmutableSet<BigDecimal> testBigDecimalTen() {
     return ImmutableSet.of(BigDecimal.valueOf(10), BigDecimal.valueOf(10L), new BigDecimal("10"));
   }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/BigDecimalRulesTestOutput.java

@@ -13,6 +13,10 @@ ImmutableSet<BigDecimal> testBigDecimalOne() {
     return ImmutableSet.of(BigDecimal.ONE, BigDecimal.ONE, BigDecimal.ONE);
   }
 
+  ImmutableSet<BigDecimal> testBigDecimalTwo() {
+    return ImmutableSet.of(BigDecimal.TWO, BigDecimal.TWO, BigDecimal.TWO);
+  }
+
   ImmutableSet<BigDecimal> testBigDecimalTen() {
     return ImmutableSet.of(BigDecimal.TEN, BigDecimal.TEN, BigDecimal.TEN);
   }