Fixed collection cache test.

Change-Id: I2cd954deeda2754408e15bd6b073ec59363e108e
diff --git a/pom.xml b/pom.xml
index fb0dc79..26308bf 100644
--- a/pom.xml
+++ b/pom.xml
@@ -229,6 +229,7 @@
 				<version>2.5.1</version>
 				<inherited>true</inherited>
 				<configuration>
+				    <argLine>-Xms512m</argLine>
 					<showWarnings>true</showWarnings>
 					<source>1.7</source>
 					<target>1.7</target>
@@ -284,7 +285,8 @@
 				<artifactId>maven-surefire-plugin</artifactId>
 				<version>2.22.1</version>
 				<configuration>
-          <useSystemClassLoader>false</useSystemClassLoader>
+          		    <useSystemClassLoader>false</useSystemClassLoader>
+          		    <argLine>-Xms512m</argLine>
 					<excludes>
 						<exclude>**/benchmark/*</exclude>
 						<exclude>**/TestWPDIndex.java</exclude>