How to validate xml in bpel process (during transformation)

In your bpel process after you pick any message/xml from any source/adapter we can validate the xml message by doing the following

Open bpel process *. bpel file in source mode and add the following attribute to transformation activity
bpelx:validate="yes"

Example:
-----------------
<assign name="Transform_DBRead_Result_To_CDM"
bpelx:validate="yes">
<?xml:namespace prefix = bpelx /><bpelx:annotation>
<bpelx:pattern>transformation</bpelx:pattern>
</bpelx:annotation>
<copy>
<from expression="ora:processXSLT('Transformation_A_To_B.xsl',bpws:getVariableData('Result_receive_InputVariable','HeadersVCollection'))">
<to variable="Variable_CDM">
</copy>
</assign>