XSLT grouping every 4 adjacent elements

I have a xml like below.

Source XML:

<?xml version="1.0" encoding="Windows-1252"?>
<XML>
  <Attributes>
    <Attribute>
      <Name>Collection</Name>
      <Value />
    </Attribute>
    <Attribute>
      <Name>A</Name>
      <Value>Testing</Value>
    </Attribute>
    <Attribute>
      <Name>B</Name>
      <Value>Blank</Value>
    </Attribute>
    <Attribute>
      <Name>C</Name>
      <Value>11</Value>
    </Attribute>
    <Attribute>
      <Name>D</Name>
      <Value>NA</Value>
    </Attribute>
    <Attribute>
      <Name>A</Name>
      <Value>Testing1</Value>
    </Attribute>
    <Attribute>
      <Name>B</Name>
      <Value>Red</Value>
    </Attribute>
    <Attribute>
      <Name>C</Name>
      <Value>12</Value>
    </Attribute>
    <Attribute>
      <Name>D</Name>
      <Value>NAT</Value>
    </Attribute>
  </Attributes>
</XML>

From the above xml how I can I do this. I only want to group them in groups of 4. So first 4 (in the source xml) element where /attribute/Name='A' - /attribute/Name='D' will be in the first group. and next 4 where /attribute/Name='A' - /attribute/Name='D' will be in the second group .... like below

Thanks in Advance

Output

 <Collection name="Collection" >
           <ComplexAttr>
                  <Attr name="A" value="Testing" />
                  <Attr name="B" value="Blank" />
                  <Attr name="C" value="11" />
                  <Attr name="D" value="NA" />
           </ComplexAttr>
           <ComplexAttr >
                  <Attr name="A" value="Testing1" />
                  <Attr name="B" value="Red" />
                  <Attr name="C" value="12" />
                  <Attr name="D" value="NA" />
           </ComplexAttr>
    </Collection>

This is a FAQ. See my link in the comments to your question. Here is a stylesheet tailored to your input and desired output:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <!--  the number of items to include in each group -->
    <xsl:variable name="group" select="4" />
    <xsl:template match="/">
        <Collection name="Collection">
            <xsl:apply-templates
                select="XML/Attributes/Attribute[not(Name='Collection')]
                                                [position() mod $group = 1]" />
        </Collection>
    </xsl:template>
    <xsl:template match="Attribute" mode="inner">
        <Attr name="{Name}" value="{Value}" />
    </xsl:template>
    <xsl:template match="Attribute">
        <ComplexAttr>
            <xsl:apply-templates
                select=".|following-sibling::Attribute[position() &lt; $group]"
                mode="inner" />
        </ComplexAttr>
    </xsl:template>
</xsl:stylesheet>

Produces:

<Collection name="Collection">
    <ComplexAttr>
        <Attr name="A" value="Testing" />
        <Attr name="B" value="Blank" />
        <Attr name="C" value="11" />
        <Attr name="D" value="NA" />
    </ComplexAttr>
    <ComplexAttr>
        <Attr name="A" value="Testing1" />
        <Attr name="B" value="Red" />
        <Attr name="C" value="12" />
        <Attr name="D" value="NAT" />
    </ComplexAttr>
</Collection>