WIP - [STATISTICS-14] - BigDecimalStatistics - Continued.
diff --git a/.travis.yml b/.travis.yml
index 41ac734..6fe9f03 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,14 +14,13 @@
 # limitations under the License.
 
 language: java
-sudo: false
 
 jdk:
   - oraclejdk8
   - openjdk8
 
-script:
-  - mvn
+install: true
 
-after_success:
+script:
   - mvn clean test jacoco:report coveralls:report -Ptravis-jacoco
+
diff --git a/commons-statistics-bigdecimal/src/main/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatistics.java b/commons-statistics-bigdecimal/src/main/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatistics.java
index a2625fc..ad5f05a 100644
--- a/commons-statistics-bigdecimal/src/main/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatistics.java
+++ b/commons-statistics-bigdecimal/src/main/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatistics.java
@@ -25,6 +25,10 @@
 public class BigDecimalSummaryStatistics implements Consumer<BigDecimal> {
 
     /**
+     * The count value for zero.
+     */
+    private static final long ZERO_COUNT = 0L;
+    /**
      * internal counter.
      */
     private long count;
@@ -46,7 +50,7 @@
      * BigDecimal#ZERO}
      */
     public BigDecimalSummaryStatistics() {
-        this.count = 0;
+        this.count = ZERO_COUNT;
         this.sum = BigDecimal.ZERO;
         this.max = null;
         this.min = null;
@@ -76,9 +80,9 @@
     public BigDecimalSummaryStatistics(long count, BigDecimal min, BigDecimal max,
         BigDecimal sum) {
 
-        if (count < 0L) {
+        if (count < ZERO_COUNT) {
             throw new IllegalArgumentException("count must be greater or equal to zero.");
-        } else if (count > 0L) {
+        } else if (count > ZERO_COUNT) {
             if (min == null) {
                 throw new IllegalArgumentException("min is not allowed to be null.");
             }
@@ -132,7 +136,7 @@
      * @param other another {@code BigDecimalSummaryStatistics}
      * @throws IllegalArgumentException in case of giving {@code null} for {@code value}.
      */
-    public void combine(BigDecimalSummaryStatistics other) throws IllegalArgumentException {
+    public void combine(BigDecimalSummaryStatistics other) {
         if (other == null) {
             throw new IllegalArgumentException("other is not allowed to be null.");
         }
@@ -176,7 +180,7 @@
      * converted to a BigDecimal.
      */
     public final BigDecimal getMin() {
-        if (this.count == 0) {
+        if (this.count == ZERO_COUNT) {
             throw new IllegalStateException(
                 "Minimum can not be calculated cause we have no values yet.");
         }
@@ -192,7 +196,7 @@
      * converted to a BigDecimal.
      */
     public final BigDecimal getMax() {
-        if (this.count == 0) {
+        if (this.count == ZERO_COUNT) {
             throw new IllegalStateException(
                 "Maximum can not be calculated cause we have no values yet.");
         }
diff --git a/commons-statistics-bigdecimal/src/test/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatisticsAssert.java b/commons-statistics-bigdecimal/src/test/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatisticsAssert.java
index 7d14dbb..79f1903 100644
--- a/commons-statistics-bigdecimal/src/test/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatisticsAssert.java
+++ b/commons-statistics-bigdecimal/src/test/java/org/apache/commons/statistics/bigdecimal/descriptive/BigDecimalSummaryStatisticsAssert.java
@@ -62,10 +62,4 @@
         return myself;
     }
 
-    public BigDecimalSummaryStatisticsAssert isEqualTo(BigDecimalSummaryStatistics expected) {
-        System.out.println("this:" + this.getClass().getName());
-
-        return null;
-    }
-
 }